On Thursday, March 2, 1995 at 2:18am CST (MET 1hr 39min), the payload bay doors were opened and the crew was given a go for orbit operations. STS-67 MCC Status Report #01 reports: The crew -- Commander Stephen S. Oswald, Pilot William G. Gregory, Payload Commander Tamara E. Jernigan, Mission Specialists John M. Grunsfeld and Wendy B. Lawrence, and Payload Specialists Samuel T. Durrance and Ronald A. Parise -- readied the shuttle and ASTRO-2 to support 15 and a half days of astronomical observations. The Blue Team of crew members -- Jernigan, Lawrence and Durrance -- will be on duty mornings aboard the spacecraft while their fellow crewmembers, called the Red Team, sleep. The Red crew members will take over duties at about 10:52 a.m.

On Thursday, March 2, 1995 at 6 a.m. CST, STS-67 Payload Status Report #01 states: (0/5:22 MET) Payload Commander Tammy Jernigan completed initial activation of the Spacelab pallet systems just before 4 a.m then began activating the Spacelab Instrument Pointing System. At 5:47 a.m., she raised it upright in the Shuttle cargo bay to face the heavens. Astronomers will use the pointing system to precisely track the stars and galaxies they study during the nearly 16-day mission.

Payload controllers and science teams at NASA's Spacelab Mission Operations Control center in Huntsville watched closely as Payload Specialist Samuel T. Durrance supplied power from the Spacelab to the telescopes shortly after 4 a.m., then started step-by-step procedures to activate the individual instruments. Samuel T. Durrance, an astronomer from The Johns Hopkins University in Baltimore, Md., is a veteran of the Astro-1 mission on STS-35 in December 1990, which was the maiden Shuttle flight for all three Astro telescopes.

On Thursday, March 2, 1995 at 8:00 a.m. CST, STS-67 MCC Status Report #02 reports: The Blue Team -- Payload Commander Tammy Jernigan, Mission Specialist Wendy Lawrence and Payload Specialist Sam Durrance will wrap up its first day on orbit shortly before noon Central time. The Red Team -- Commander Steve Oswald, Pilot Bill Gregory, Mission Specialist John Grunsfield and Payload Specialist Ron Parise will then continue with the science activities.

On Thursday, March 2, 1995 at 5:00 p.m. CST, STS-67 MCC Status Report #03 reports: Activation and calibration of the Astro-2 ultraviolet telescopes are continuing slightly behind schedule following a steering jet leak that has twice forced closure of the instruments protective doors. The leak is in a reaction control system thruster designated R4R, a jet in the right aft orbital maneuvering system pod that is aimed to the right of the shuttle. Flight controllers worked with the crew to close the manifold that supplies oxidizer and fuel to that jet, which effectively stopped the leak.

The doors on the Hopkins Ultraviolet Telescope, the Wisconsin Ultraviolet Photo-Polarimeter Experiment and the Ultraviolet Imaging Telescope were first closed to protect the instruments from any remaining oxidizer coming out of that jet after the manifold was closed. Once the thruster's propellant lines had been evacuated, the telescope doors were reopened. The doors were briefly closed again while residual propellant downstream of the closed manifold dissipated, but are now open and all scheduled operations have resumed.

The failed jet, which is not being used to position the orbiter for its science operations, is not a safety hazard in any way, and does not affect the mission duration. The flight control team is looking at options in dealing with the jet, but has not yet decided whether any additional actions will be necessary.

On Thursday, March 2, 1995 at 6 p.m. CST, STS-67 Payload Status Report #02 reports: (0/17:22 MET) Payload Commander Tammy Jernigan continued checkout of the Instrument Pointing System, on which the three ultraviolet telescopes are mounted. The crew reported success with their first automatic star identification procedure at about 6:30 a.m. CST, verifying that the pointing system can center accurately on the celestial objects Astro-2 science teams will choose to view.

Payload Specialist Sam Durrance finished activating the Ultraviolet Imaging Telescope, then completed the more complicated procedures to put the Hopkins Ultraviolet Telescope into operation. Pilot Bill Gregory, Mission Specialist John Grunsfeld and Payload Specialist Ron Parise took over operations from the first crew at 11:30 a.m. The two crew teams are working 12-hour shifts, so astronomical observations can continue around the clock.

Activation and verification of the Wisconsin Ultraviolet Photo- Polarimeter Experiment (WUPPE) detector was delayed by difficulties keeping it aligned with a test target, but the WUPPE science team and Parise corrected the problem after several attempts. Alternate Payload Specialist John-David Bartoe reported from the ground, "Ron, the WUPPE folks are ecstatic down here, and they like everything they see."

Astro telescope verification was interrupted briefly at around 1:15 p.m., when ground controllers closed the telescope doors to prevent contamination by oxidizer leaking from one of Endeavour's reaction control system thrusters. The thruster was closed less than hour later, and Parise reopened the doors.

During the telescope shutdown, Grunsfeld continued checking out the Instrument Pointing System and the Image Motion Compensation System, which keeps the WUPPE instrument and the imaging telescope on target despite subtle disturbances. Johnson Space Center controllers declared the Instrument Pointing System operational at 1:53 p.m., and they transferred control of the equipment to the Marshall Center payload team for science activities.

Parise and Grunsfeld then began an extended procedure called Joint Focus and Alignment, one that is unique for space telescopes to the Astro-2 payload. Since all three instruments often make simultaneous observations of the same objects, science teams must be certain they are pointing in precisely the same direction and are in near-perfect focus. Final focusing and calibration of the Hopkins and Wisconsin instruments will continue through the first half of the upcoming shift. Astro-2 observations of the ultraviolet sky will then begin.

On Thursday, March 3, 1995 at 8 a.m. CST, STS-67 MCC Status Report #04 reports: The Instrument Pointing System continues to perform well. The preliminary assessments of IPS stability and accuracy show that the system is operating well. Control loop software, gyro and accelerometer response have been good, and Optical Sensor Package performance has been excellent with two of three trackers slightly exceeding performance expectations. IPS controllers in Houston are currently tracking no problems or issues, and team members do not anticipate a change in the IPS's performance.

The payload control team at the Marshall Space Flight Center, Huntsville, Ala., however, is looking at several reported excursions in ASTRO-2's pointing abilities that have required the crew to repeatedly fine tune the instruments after establishing the platform's reference point for celestial observations. Controllers in Houston and Huntsville are working on procedures that will reduce the number of calibrations needed.

On Thursday, March 2, 1995 at 6 a.m. CST, STS-67 Payload Status Report #03 reports: (1/5:22 MET) Pilot William Gregory maneuvered the orbiter into different attitudes, or positions throughout the night. Payload Commander Tammy Jernigan, Mission Specialists John Grunsfeld and Wendy Lawrence, and Payload Specialists Ronald Parise and Samuel Durrance coordinated with science teams at Marshall Space Flight Center in Huntsville, Alabama, performing procedures to align and focus the Hopkins Ultraviolet Telescope (HUT), Ultraviolet Imaging Telescope (UIT) and Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) last night. Approximately 23 hours after launch, the Astro-2 instruments, nestled in Endeavour's cargo bay, were being calibrated before observations of the invisible universe began.

While still in the calibration, or Observatory Commissioning Phase, two of the three Astro-2 instruments, HUT and UIT science teams, were locked onto an ancient supernova remnant. This supernova remnant is the result of a powerful explosion, which ended the life of a massive star many thousands of years ago, and was used as a calibration target for the telescopes. During this mission, HUT's spectrographs will help scientists determine temperatures, densities and chemical compositions of gases in the supernova remnant while the UIT will image the filaments of excited gas in the supernova remnant. HUT Guest Investigator Dr. John Raymond of Cambridge, Mass., will obtain information about the shock waves energizing these nebulae.

The first science observation for Astro-2, a supernova remnant known as Cygnus Loop, began just before the Space Shuttle Endeavour crossed the South Atlantic Anomaly early this morning. Since this South Atlantic area is a region of intense particle radiation that can affect detectors in the telescopes, crew members secured the instruments until the orbiter had moved away from the anomaly. The observation of Cygnus Loop then continued until the supernova remnant was out of the telescopes' field of view.

The HUT telescope continues in the calibration phase. HUT, developed at the Johns Hopkins University in Baltimore, Maryland, has a 36-inch mirror to focus ultraviolet light into a spectrograph in the middle of the telescope. This spectrograph "spreads" light into a spectrum, or band of colors, based upon the wavelength of the light. Principal Investigator Dr. Arthur Davidsen and his colleagues will study these spectra to determine the chemical composition, temperature, densities and motion of the celestial objects being observed during Astro-2.

The UIT made its first deep, wide-field photographs in ultraviolet light overnight. After Endeavour lands, Principal Investigator Theodore Stecher and the UIT science team in Greenbelt, Maryland, will study the images made by this telescope during this 16-day mission, looking for answers to astronomical questions such as the shapes of nearby galaxies in the ultraviolet, the properties of massive hot stars in these galaxies, the evolution of low-mass stars in clusters, and the nature of the dust and gas that fill the space between stars.

On Friday, March 3, 1995 at 4 p.m. CST, STS-67 MCC Status Report #05 states: Commander Steve Oswald and Pilot Bill Gregory set up the Middeck Active Control Experiment (MACE) hardware. MACE is a five-foot long flexible beam with mock satellite instruments mounted at either end. It will float free in the shuttle's lower deck, and the astronauts will measure how disturbances caused by one instrument affect the performance of the instrument at the experiment's opposite end. The information gathered will assist engineers in designing more stable space structures. The crew tested the MACE equipment and its communications with the ground. Some problems were experienced initially in sending information from the ground to the experiment during checkouts, however such an uplink of information is not planned or needed for the MACE operations for several days. Meanwhile,

On Friday, March 3, 1995 at 6 p.m. CST, STS-67 Payload Status Report #04 states: (1/17:22 MET) The three Astro-2 telescopes have begun their methodical exploration of the ultraviolet universe, as scientists aboard the Shuttle Endeavour and at Spacelab Mission Operations Control fine-tune the Astro-2 equipment and procedures to optimize pointing stability. This afternoon, payload controllers eliminated a drift in that had been detected in the Instrument Pointing System by adjusting the target acquisition procedure.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) got its first turn as the primary instrument this morning. Its observations of a calibration star, Beta Cassiopeiae, showed that the instrument optics, spectrometer and motion compensation system are working well. The team also will use the star as an unpolarized standard against which other observations can be measured.

The WUPPE team also made the first of several planned observations of the supergiant star P Cygni. These observations will help scientists determine how this type of star ejects material into interstellar space, whether uniformly in the shape of a shell, or in the form of plumes or blobs of material. Team members say this is an interesting time to observe P Cygni, because recent ground-and space-based observations indicate the star, which has been relatively inactive for the past 100 years, has entered a more active phase of its life. Because the star can vary on a day-to-day basis, observations made later in the mission will give astronomers an important set of measurements over a relatively short time.

During its time block, the Hopkins Ultraviolet Telescope (HUT) observed a celestial "odd couple," two stars with radically different temperatures in orbit around one another, called a symbiotic star system. The system HUT observed today, EG Andromedae, is made up of an orange-colored giant star co-orbiting with a tiny, exceptionally hot blue star. Astronomers had not realized how hot the smaller star is until an instrument aboard one of the Voyager planetary probes picked up its strong ultraviolet emissions.

The HUT team also checked out the sensitivity of their spectrometer by viewing a white dwarf star, known as HZ 43, which they had observed during Astro-1. At a very late stage of its evolution, the star has burned up nearly all of its fuel. Astronomers understand physical conditions in the atmospheres of HZ 43 and similar white dwarfs well enough that they can calculate very precisely how much ultraviolet light they emit. This makes such stars useful for confirming the HUT instrument's calibrations.

The Ultraviolet Imaging Telescope (UIT) observations included images of globular clusters, massive spherical concentrations of stars that are the oldest class of objects in our Milky Way Galaxy. "These clusters appear to be 16 to 19 billion years old, despite recent Hubble indications that the universe is only about 10 billion years old," said UIT astronomer Dr. Steve Maran. "UIT images of globular clusters from Astro-1 revealed a previously unknown class of stars, visible only in the ultraviolet, which may have skipped a stage in stellar evolution as we had understood it. We're hoping follow-up observations of globular clusters during Astro-2 will give us a better understanding of stellar physics."

On Saturday, March 4, 1995 at 6 a.m. CST, STS-67 Payload Status Report #05 reports: (2/5:22 MET) The Hopkins Ultraviolet Telescope (HUT) led the observations of several celestial objects, starting with AX Persei, a double star system consisting of a red star paired off with a blue star in what is known as a symbiotic binary. This means that the two stars differ greatly in their temperature ranges. They are believed to be a pair in which gas from a large, cool star falls onto a smaller, but more massive companion. Not much is known about how these stars interact, and data from these observations will help improve current measurements of the hot star component's temperature and gas emissions.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) also obtained "great observations" of the AX Persei star system, according to WUPPE guest investigator Dr. Regina Schulte-Ladbeck. In a live interview with TV station WPXI in Pittsburgh, Pennsylvania, Dr. Schulte-Ladbeck described the instrument's view of the stellar pair as "picture perfect from an operational point of view."

Dr. Schulte-Ladbeck also used HUT and WUPPE to obtain spectral measurements of a Wolf-Rayet star known as EZ Canis Majoris. Wolf-Rayet stars are thought to represent one of the final phases of evolution in massive stars that are between 100,000 and 1,000,000 times as bright as the Sun. Wolf-Rayet stars have powerful stellar winds, or emissions of ionized gas, that quicken the stars' aging process. The composition of these stellar winds is also important because the elements they contain play a significant role in forming the basic chemistry of life. According to Dr. Schulte-Ladbeck, last night's measurements alone, of the strength and composition of this stellar wind, have already yielded "more information about EZ Canis Majoris than we ever got on Astro-1."

The Astro-2 scientists also turned their attention to one of their prime targets of investigation, the brightest known Seyfert galaxy, NGC 4151. Seyfert galaxies are known for their extremely bright and compact centers and radiate energy most strongly in the ultraviolet and X-ray wavelengths.

Ultraviolet Imaging Telescope (UIT) observations included images of a globular cluster, NGC6752, and a spiral galaxy, M101. Globular clusters are collections of relatively old stars, and they are particularly suitable for observations by UIT due to the presence of hot stars which emit most of their radiation in the ultraviolet range. This enables UIT astronomers to locate hot white dwarf stars, hot binary systems and objects associated with sources of X-rays.

Spiral galaxies, like our Milky Way, are flattened discs with central bulges or nuclei from which the galaxies' arms extend. M101 is a big spiral galaxy with spiral arms that are not tightly wound. UIT's ultraviolet imaging offers a powerful new tool for the study of this spiral structure, since it emphasizes hot stars, hydrogen and dust.

Early in the morning, the Astro-2 instruments made observations of the Cygnus Loop, a middle-aged supernova remnant. A supernova is one of the most powerful explosions in the universe, and it occurs at the end of a very massive star's life after the star's fusion reaction stops. The Cygnus Loop is of particular interest because it reveals details about the structure and speed of shock waves from the explosion as they travel through the interstellar medium.

Jupiter had became a focus of investigation earlier in the evening, especially for the HUT science team who obtained very good spectral data on the planet's equator. The planet is believed to have a reservoir of heat energy left over from its creation, since Jupiter radiates twice as much energy as it receives from the Sun. HUT scientists are particularly interested in the planet's immense magnetosphere, a region of charged particles controlled by Jupiter's magnetic field.

On Saturday, March 4, 1995 at 1 p.m. CST, STS-67 MCC Status Report #06 reports: During the past shift, the crew received word from scientists who designed the Australian ultraviolet experiment that is flying in two Getaway Special canisters in the cargo bay. The experimenters reported they have achieved 100 percent of desired observations and expressed a sincere thanks and appreciation for the support they received during this mission. In addition, Jernigan and Lawrence participated in an interview with National Public Radio as Durrance supported the Astro-2 observations.

On Sunday, March 5, 1995 at 6 a.m. CST, STS-67 Payload Status Report #07 reports: (3/5:22 MET) Commander Steve Oswald maneuvered the Space Shuttle Endeavour to enable the Hopkins Ultraviolet Telescope (HUT) to lead an observation of a mysterious star in the constellation Cassiopeia. This star, known to astronomers as KPD0005, belongs to a class of planetary nebulae, or clouds of gas with bright centers, that includes some of the hottest stars known. So hot are these stars' surfaces, in fact, that their elements are completely ionized, making their chemical composition difficult to analyze. Only ultraviolet astronomy, such as the Astro-2 instruments employ, can yield answers to questions about the chemistry and evolution of this type of star.

Following this, the HUT science team then turned their attention back to the search for signs of interstellar helium, using light from a distant quasar, known as 1700+64. Since it is believed that helium was formed in the Big Bang at the beginning of the universe, the actual detection of intergalactic helium would probably be the most significant scientific result that the HUT observations might produce. Because of the enormous distances of these objects, the targets are necessarily faint, and such observations are the most difficult that HUT scientists will attempt. They are also the most sensitive measurements ever made for interstellar helium.

Another priority for the HUT scientists involves the study of Type II Seyfert galaxies. These galaxies, such as NGC1068 which was observed last night, have bright centers that emit energy over a broad range of frequencies. It is believed that the core of NGC #1068 is ionized by shock waves of gas moving at hundreds of miles per second, and the ultraviolet observations by the Astro-2 instruments are testing this hypothesis.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) team has also taken great interest in NGC 1068 and made some very difficult indirect observations of the galaxy's core using the electron cloud above the galaxy as a polarization mirror. "By observing the diffuse light reflected from the electron cloud, we are able to take measurements of the otherwise obscure nucleus of the galaxy," said WUPPE co-investigator Karen Bjorkman. On Astro-1, observations by WUPPE helped confirm that a thick torus, or doughnut-shaped cloud, exists around the nucleus of NGC #1068, while HUT observations showed unexpectedly high temperatures near the torus.

Early in the morning, WUPPE scientists also took the opportunity to view a couple of interactive binary star systems, V356 Sagittarii and Vela X-1. A binary star system consists of a pair of stars that orbit each other. In the case of an interactive binary, the stars stay so close to each other that they actually exchange gases.

Astronomers believe that in an X-ray binary such as Vela X-1, a neutron star (or pulsar) gravitationally strips material off of its companion star. A lot of the stripped material settles into orbit to form an oval disc shape. Polarization measurements by WUPPE allow scientists to measure the size and shape of this disc, and it also provides information about the stars involved. As WUPPE Principal Investigator Arthur Code observed, "the unique feature of interactive binary stars' polarization is that we can use that information to calculate the mass exchanged between the stars." Last night's observations were enhanced by the fact that the Astro-2 instruments could view both members of each binary side by side as they interact.

The Ultraviolet Imaging Telescope (UIT) made observations of an open cluster called NGC #3532. This is a diffuse cluster of stars and is believed to be less than ten million years old. Because UIT's field of view is well matched to the sizes of most clusters in our Milky Way Galaxy, UIT scientists are able to perform ultraviolet observations of many stars at the same time. UIT observers are searching for ultraviolet counterparts to X-ray sources as well as for white dwarfs and other faint, hot stars. These ultraviolet-bright objects are of great interest for several reasons: they can be used as probes of the interstellar medium; they can be used to provide highly accurate distance measurements to the clusters; and they will enhance understanding of the chemical evolution of the Milky Way Galaxy.

UIT also imaged several ancient globular clusters in our Milky Way galaxy as well as other nearby spiral galaxies. The latter observations will be used to further our understanding of star-formation in the spiral arms of these galaxies.

On Sunday, March 5, 1995 at 1 p.m. CST, STS-67 MCC Status Report #07 stated that there has been some indications that the crew's stationary bicycle exercise is imparting some vibration to the shuttle that is interfering with the Instrument Pointing System's ability to precisely direct the Astro-2 telescopes at their targets. The crew is being asked to schedule exercise a little earlier so that the vibration has stopped by the time Endeavour moves into darkness and celestial observations must resume.

On Sunday, March 5, 1995 at 6 p.m. CST, STS-67 Payload Status Report #08 reports: (3/17:22 MET) Both the Hopkins telescope and the Wisconsin Ultraviolet Photo- Polarimeter Experiment (WUPPE) examined two Seyfert galaxies, Markarian 279 and Fairall 9, in a study that could provide insights into some of the most powerful events in the universe. Named for Vanderbilt University astronomer Carl Seyfert, who identified this type of galaxy in 1943, Seyferts have extremely bright, compact cores containing clouds of gas moving at thousands of miles per second. Astronomers theorize that supermassive black holes would be the only source capable of generating the immense power given off by these objects.

The HUT team also practiced acquiring quasar Q 1542+54 to refine procedures for locating it efficiently in future observations. Their success gives them an additional illumination source to use in their search for intergalactic helium. Yesterday, they successfully locked onto the quasar 1700+64, which will likely remain their primary target for the study.

Several observations today examined the dust and gas from which stars form. HUT selected a reflection nebula and the star which illuminates it. The star, AE-Aurigae, is a very hot, massive blue star with surface temperatures from 50,000 to 70,000 degrees Fahrenheit (28,000 to 40,000 Kelvin). Light from the star illuminates a cloud of dust surrounding it, creating a bright, colorful nebula. Observation by the Astro telescopes may help determine the composition of the dust and the sizes and shapes of the grains.

The first observation of the day with WUPPE as the lead instrument was HD 50138, viewed after Mission Specialist John Grunsfeld and Payload Specialist Ron Parise took over science crew duties. This pre-main-sequence star is thought to be a young object, several times more massive than our sun, that has just formed out of the interstellar gas and dust. Polarization measurements should help show the shape of the nebula which surrounds the star and indicate where it is coming from. The study should help astronomers learn more about the ways in which young stars form and how their birth clouds eventually disperse.

The WUPPE team also observed the star HD 197770, an interstellar polarization probe. The star serves much like a flashlight, illuminating the vast and normally invisible clouds of dust and gas in the space between stars. The materials in these swirling clouds are, in essence, the stuff of past and future stars. Over eons, as stars grow old, they kick out vast amounts of very hot material -- mostly gas and dust -- into space. These materials form into clouds, and over many thousands of years the clouds collapse and form new stars. By determining how much the ultraviolet light passing through the clouds is polarized, or vibrating in a preferred direction rather than randomly, WUPPE can provide further clues as to the nature of this interstellar dust.

Phi Persei, a hot, rapidly spinning star, was another subject of study for WUPPE. The star exhibits an unusual ultraviolet spectrum that may be caused by a shell of gas around the star, possibly the remains of a layer that has been spun off the star by its rapid rotation. This shell is thought to be in the form of a disk around the equator of the star, and the scattering of starlight by the disk polarizes the light.

Celestial objects chosen for observation by the Ultraviolet Imaging Telescope (UIT) included M31, the famous Andromeda galaxy in our "local group," the cluster of galaxies which includes our own Milky Way. UIT researchers are conducting ultraviolet studies of the structure of local group galaxies. They will also examine the photographs to study the physics of star formation contained in these galaxies.

The UIT team also selected various kinds of open and globular star clusters, groups of stars formed from the same basic material at the same time. By comparing clusters of different ages and by looking at different types of stars of the same age, astronomers can learn a great deal about how each type of star changes in its lifetime.

On Monday, March 6, 1995 at 6 a.m. CST, STS-67 Payload Status Report #09 reports: (4/5:22 MET) The Astro-2 instruments spent the fourth night of the mission viewing spiral, radio and other types of galaxies as well as two types of binary star systems and some individual stars. Also, the search for intergalactic helium continued as these telescopes observed some of the most distant objects in the known universe. All the Astro-2 instruments, Spacelab, and the Instrument Pointing System continue to perform well.

"I think we've just set a world record for acquisition," commented Mission Specialist John Grunsfeld upon the swift targeting of GD394, a white dwarf star in the Cygnus constellation, for the Hopkins Ultraviolet Telescope (HUT). Earlier in the evening, an edited StarView software package was uplinked to Space Shuttle Endeavour. This upgrade made what Alternate Payload Specialist Scott D. Vangen called, "a world of difference" in improving acquisition times for the Astro-2 instruments.

White dwarf stars, such as GD394, have magnetic fields stronger than any that can be formed in laboratories on the earth. They are interesting for astronomers because they provide a laboratory for studying the effects of strong magnetic fields on radiation. One such effect is that the light coming from these objects is highly polarized, or is vibrating in a single direction.

HUT scientists made further ultraviolet observations of the bright quasar 1700+64 in the hope of discovering intergalactic helium. Astronomers have been searching for evidence of intergalactic matter left over from the formation of the universe for 30 years, and HUT was originally designed with this goal in mind. If ionized helium is present in the space in front of a quasar, it should block out the helium signature in HUT's far ultraviolet spectrum of the quasar-- thus establishing the existence of the ionized helium in the intergalactic medium.

Binary star systems, or pairs of mutually orbiting stars, again became prime objects for observations selected by the HUT science team. Earlier in the evening, the HUTand Wisconsin Ultraviolet Photo Polarimeter Experiment (WUPPE) instruments looked at the symbiotic binary Z Andromedae, located in the constellation Andromeda, as part of the joint HUT/WUPPE investigator program. Symbiotic stars are binary systems in which the component stars have radically different temperature ranges. Guest Investigator Dr. Brian R. Espey used HUT and WUPPE to study the ultraviolet spectrum of Z Andromedae, in order to improve measurements of the hotter star's temperature.

The first ever ultraviolet observations of a very spectacular binary star system, Nova Aquilae, were made early in the morning by members of the WUPPE science team. This system, consisting of a white dwarf and a more normal star, became a bright nova, or a new explosive object, just about a week ago. This binary's explosions occurred due to the interactions between the two stars. Specifically, hot gas from the normal star was pulled by gravity toward the white dwarf star's surface. As this material collected on the white dwarf's surface, thermonuclear fusion took place, resulting in sudden and extremely bright explosions. As WUPPE co-investigator Chris Anderson described this process, "a week ago it was a faint, unobtrusive star....then it suddenly became thousands of times brighter."

Another target observation for WUPPE scientists over night included one of the most beautiful and colorful types of objects known. Reflection nebula NGC7023 is the brightest of its kind, in which starlight is scattered by dust grains, producing brilliant illumination in its cloud. The WUPPE team is using its observations of this nebula to further study the nature of dust grains in interstellar space.

Celestial objects chosen for observation by the Ultraviolet Imaging Telescope (UIT) last night included the spiral galaxy NGC1097 and the radio galaxy Centaurus A. Centaurus A is the nearest active galaxy to our own and is one of the most prominent radio sources in the Southern Hemisphere. UIT scientists are examining it to study star formation processes and stellar evolution there. Radio galaxies like Centaurus A emit radiation a million times stronger than galaxies like ours. Many questions surround radio galaxies, including those concerning the possible relationships between these galaxies, quasars and other energetic sources.

UIT scientists also selected a cluster in the Small Magellanic Cloud, an irregular galaxy, as a target. Eighteen targets within the local group of galaxies are candidates for observation on Astro-2, and UIT is conducting ultraviolet studies on their structures. These scientists are also studying the physics of star formation in supernova remnants contained in these galaxies. While UIT used its large field of view to image regions of the Small Magellanic Cloud, HUT observed the supernova remnants within it. HUT's large spectrograph apertures permit observations of the remnants' temperature, density and chemical composition.

On Monday, March 6, 1995 at 5 p.m. CST, STS-67 MCC Status Report #09 reports: The STS-67 astronauts continue to operate the ASTRO-2 payload and also worked with several microgravity experiments and talked with students on the ground around the world through the Shuttle Amateur Radio Experiment. The Blue Team -- Payload Commander Tammy Jernigan, Mission Specialist Wendy Lawrence and Payload Specialist Sam Durrance -- worked with the Commercial Materials Dispersion Apparatus Instruments Technology Associates Experiments (CMIX) and checked on the health of the Protein Crystal Growth biotechnology experiments.

Lawrence also sent special greetings to the 19 men and women who reported to the Johnson Space Center today representing the Astronaut Class of 1995. The Red Team -- Commander Steve Oswald, Pilot Bill Gregory, Mission Specialist John Grunsfeld and Payload Specialist Ron Parise -- went on duty about noon CST. As Grunsfeld and Parise supported Astro-2 observations, Oswald coordinating a successful data transfer that will help Middeck Active Control Experiment scientists and engineers design large spacecraft. Gregory practiced for the end of the 15 1/2 day mission on the PILOT landing simulator.

On Monday, March 6, 1995 at 6 p.m. CST, STS-67 Payload Status Report #10 reports:(4/17:22 MET) Two cataclysmic variables were on today's menu of HUT targets. These are systems of two stars, orbiting extremely close together, where a white dwarf in the final stage of its life cycle is paired with a more "normal" star somewhat similar to our sun. Occasionally their interactions create an outburst, or sudden increase in energy emissions. This interchange of matter between stars, called accretion, is of great interest to the HUT and Wisconsin Ultraviolet Photo-Polarimeter Experiment teams because it is essential to many astrophysical situations such as the generation of energy by quasars.

This morning, the Astro telescopes observed VW Hydri, a cataclysmic variable which undergoes outbursts of energy roughly every 20 days. Though it was in a relatively low state of activity today, VW Hydri will be monitored at intervals throughout the mission in hopes of getting measurements in both an outburst and a non-outburst stage. This afternoon, the teams viewed another variable, YZ Cancri, which is located in the constellation Cancer.

The telescopes made two observations of elliptical galaxy M 105 in the constellation of Leo the Lion. HUT studied the nature of stars that put out an unexpected amount of ultraviolet light in this type of galaxy. HUT observations from Astro-1 indicate it comes from older, low mass stars in a previously unknown stage of their evolution.

Individual stars chosen for viewing by HUT ranged from massive stars to compact white dwarfs. Observations of the hot, massive O-type star HD 94963, in the Southern Hemisphere constellation Carina, will be added to an "atlas" of hot stars which may assist in stellar population studies in galaxies. The white sub-dwarf star, Schweizer-Middleditch, was too close to the sun to be observed on Astro-1, so Astro-2 astronomers were particularly pleased to observe it today. It lies behind the supernova remnant SN1006, which is the debris of a star that exploded in 1006 A.D. HUT scientists are studying the star's spectrum for signs that its light is being absorbed by iron in the supernova remnant. Theories predict that a large quantity of iron was ejected by the exploding star.

Other observations in the HUT time block included observations in two parts of the Cygnus Loop supernova remnant, the leftover gas from a stellar explosion some 20,000 year ago. Seyfert galaxy Markarian 3 also was studied. Such active galaxies have unusually bright centers that resemble the more distant and more luminous quasars, and they are believed to harbor massive black holes.

The Ultraviolet Imaging Telescope (UIT) took images for an ultraviolet census of "Selected Area 57," a portion of the sky that has been intensively mapped at many other wavelengths. "This is one of two parts of the sky that astronomers all over the world have agreed to study as closely as possible with every new technology that comes along," said UIT Team Member Dr. Steve Maran. UIT's wide-field images should provide new information on faint objects that have not yet been catalogued. The UIT team will count galaxies down to faint ultraviolet magnitudes and search for quasars, for galaxies that are receding very quickly as the universe expands, and for distant clusters of star-forming galaxies. "If we see something we don't understand, we can go back and look at images made in other wavelengths to help define it," said UIT Principal Investigator Ted Stecher. "It's something like using the Rosetta stone to decipher something that was previously unknown .

UIT made images for two other science programs that could shed light on the life cycles of stars. The instrument photographed a globular cluster known as NGC 6752. Ultraviolet images will pick out hot stars, at an unusual stage of their evolution, from the tightly grouped assembly of old stars in the cluster. UIT also viewed the spiral galaxy NGC 3351. The arms of spiral galaxies, which look something like cosmic pinwheels, are made up of interstellar matter and bright young stars. The images should be useful to ultraviolet astronomers in assessing the amount of star formation in progress within the galaxies.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) team reported that one of last night's observations seems to confirm a surprise finding from Astro-1. According to WUPPE Co-Investigator Dr. Geoff Clayton, the team again saw evidence of two types of polarized "dust" in an interstellar cloud. An Astro-1 observation had indicated that some parts of the dust were like grains of sand, while others were more like soot. Ultraviolet radiation reflected from both types of grains was polarized, or vibrating in a preferred direction, indicating that both were lined up to the magnetic field. But until last night, no other observation had detected polarization in the "soot." "Last night, we saw a 'bump' in our polarization measurements just where it was on Astro 1," said Clayton. "We hope to see more bumps on later observations. If we find out this is real, we'll have to go back to the drawing board and find out why these grains are aligned as they are."

On Tuesday, March 7, 1995 at 9 a.m. CST, STS-67 MCC Status Report #10 reports: Earlier this morning, flight controllers did some troubleshooting after a circuit breaker tripped, cutting power to a portion of the Commercial Materials Dispersion Apparatus Instrumentation Technology Associates Experiment (CMIX). When Lawrence reset the circuit breaker on the middeck experiment and repowered the heater controller, ground controllers noticed a short. Lawrence subsequently was directed to turn off the heater, which maintained a slightly higher temperature (20 degrees Centigrade vs. 4 degrees Centigrade) for a portion of the Commercial Refrigerator Incubator Module (CRIM). three of the four experiment trays already had been chemically fixed, and scientists won't know until after landing what affect the heater loss will have on the samples. The CMIX/CRIM experiments which require no heat, referred to as the "cold" experiments, were unaffected by this event.

Other activities performed by the Blue Team include a successful alignment of the inertial measurement units which was performed by Lawrence, and a 12-hour water dump using the flash evaporator system was initiated this morning.

On Tuesday, March 7, 1995 at 6 a.m. CST, STS-67 Payload Status Report #11 reports: (5/5:22 MET) Crew members for the second Astro Observatory (Astro-2) mission spent a busy fifth night in space, working with three unique ultraviolet telescopes to help scientists on Earth learn more about the universe. Pilot William Gregory and Mission Specialist Wendy Lawrence maneuvered the Space Shuttle Endeavour into different orbital positions as Payload Commander Tammy Jernigan, Mission Specialist John Grunsfeld, and Payload Specialists Ronald Parise and Sam Durrance aligned the telescopes nestled in Endeavour's payload bay.

From the Marshall Space Flight Center in Huntsville, Ala., the science teams for the Hopkins Ultraviolet Telescope (HUT), Ultraviolet Imaging Telescope (UIT) and the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) watched video from the HUT target acquisition camera onboard the Shuttle while they calibrated their instruments. During this calibration period, in which HUT was pointed at a hot dwarf star in the constellation Auriga, scientists were able to check the data from their telescopes against previous observations.

Three types of galaxies were observed by the Astro-2 telescopes overnight to help scientists understand more about the formation of stars in a galaxy system. UIT used both of its onboard cameras to make images of these galaxies in both the long and short wavelength ranges. A prime target for UIT was a globular cluster in the constellation Carina. This cluster is a massive spherical concentration of stars containing up to several hundred thousand stars. This group of stars, which is extremely old, provides astronomers with information about the latter part of the evolution of stars.

HUT and WUPPE observed a massive blue star called Psi Persei, a luminous star that spins rapidly and has outer layers that show evidence of being peeled off by their stellar winds. Previous observations have suggested that these gas-laden winds are strongest near the equator of these rapidly spinning stars. Psi Persei has an unusual ultraviolet spectrum that may be caused by a shell of gas around the star, possibly the remains of the layer that has been peeled off the star. Scientists hope to accurately determine this type of star's temperature (in order to analyze its atmospheric emission), search for stellar winds and study absorption in the interstellar medium, gas and dust between these stars.

HUT and WUPPE also used a bright star much like a flashlight to illuminate the gas and dust between stars. This type of observation will help scientists understand more about the chemical composition and physical nature of the dust and gas between stars in our Milky Way galaxy. During the first Astro mission, astronomers learned that some parts of our galaxy seem to have dust grains that resemble tiny hockey pucks, while other parts seem to have a mixture of several sizes, shapes and kinds of dust grains. During Astro- 2, WUPPE Principal Investigator Dr. Arthur Code hopes to determine whether different conditions in some parts of the galaxy affect the formation of these dust grains.

The science teams for HUT, UIT and WUPPE observed video from the HUT target acquisition camera as their instruments measured a supernova remnant known as Cygnus Loop. This supernova remnant, in the constellation Cygnus, the Swan, is from a star that exploded many years ago. Both cameras of the UIT imaged the supernova remnant in both the short ultraviolet and long ultraviolet ranges. Guest Investigator Dr. John Raymond is using HUT to obtain information about shock waves the physics of collisionless shocks, the destruction of grains in shocked gas, instabilities behind radiative shocks and shock wave parameters.

The Astro-2 ultraviolet telescopes also observed a Wolf-Rayet star, thought to represent one of the final phases in the evolution of massive O and B stars, which have between 100,000 and 1,000,000 times the radiance of the sun, with temperatures up to 100 times greater. One of the most unusual features of this type of star is that it has almost no dark, or absorption, lines in its spectrum, only bright, broad emission lines.

The three Astro-2 ultraviolet telescopes also gathered information about spiral galaxies during the night. Guest Investigator Dr. Wendy Freedman is using the UIT to image several large, face-on (top or bottom view) galaxies in the far- and near-ultraviolet spectrum. Freedman will combine UIT images gathered on both the Astro-1 and Astro-2 missions to create a digital atlas of spiral galaxies. Data gathered about galaxies will also be used to study the similarities between the types of galaxies viewed by the Hubble Space Telescope in the visible and ultraviolet spectrums.

On Tuesday, March 7, 1995 at 4 p.m. CST, STS-67 MCC Status Report #11 reports: Commander Oswald transferred data from the ground to the orbiting Middeck Active Control Experiment via a high-speed air-to-ground link as Gregory took care of orienting the shuttle for its Astro-2 observations and performed housekeeping duties.Grunsfeld and Parise each were scheduled for some off-duty time.

On Tuesday, March 7, 1995 at 6 p.m. CST, STS-67 Payload Status Report #12 reports: (5/17:22 MET) The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) and Hopkins Ultraviolet Telescope (HUT) viewed Wolf-Rayet star HD 191765 twice this morning, completing a set of observations begun last night. "This is a fairly faint star, so we are observing it four times to get all the information we need," explained Guest Investigator Dr. Regina Schulte-Ladbeck of the University of Pittsburgh. "We know this star's polarization varies over time, so we put all the observations within a 12-hour period in order to make them as nearly the same as possible." Schulte-Ladbeck noted that the first observation showed very high ultraviolet polarization, and she feels confident that all four data sets will yield the same result.

Wolf-Rayet stars are thought to be a final life stage of very hot, massive and luminous stars. Powerful stellar winds cause matter to be lost from them, making them less and less massive over time. Schulte-Ladbeck is studying the mechanism of mass loss from the stars, as mass is returned to the interstellar medium and new stars are formed. "Wolf-Rayets are depositing chemically processed matter containing elements like carbon, nitrogen and oxygen for the next generation of stars, so the new stars will be different," she explained.

This afternoon, WUPPE and HUT viewed EZ Canis Majoris, a much brighter Wolf-Rayet which was observed for a briefer time during Astro-1. Ultraviolet polarization studies can help astronomers determine the shape of the material being thrown out from the star, so they can formulate a three- dimensional "map" of its structure.

The WUPPE instrument also focused on the bright ultraviolet star HD 25090 to illuminate the interstellar medium for their polarization study of the dust between stars. Determining characteristics of interstellar dust will help astronomers make allowances for the existence of this obstructing matter when studying other objects and to study its function as the source of new stars.

All three telescope teams joined today's observations of two active galaxies, thought to have supermassive black holes at their centers. NGC 4151 is a Seyfert-1 type galaxy, which emits very bright ultraviolet radiation. NGC 1068 is a Seyfert-2, with ultraviolet emissions that are not as strong. "Astro-1 and Hubble Space Telescope observations suggest there are opaque disks of cold gas around the cores of these galaxies," said HUT team member Dr. Gerard Kriss. "It could be that there is no difference in the two Seyfert types, except that we're viewing Seyfert-2's from the side with the gas disk obscuring the hot core, and we see Seyfert-1's from the top with our view of the hot gas unobstructed. It's something like not being able to see the hole in a donut when you look at the donut from the side." Actually, Kriss said, NGC 4151 is in the "twilight zone" of Seyferts, exhibiting unusual characteristics that suggest it might be tilted at an intermediate angle to Earth.

"NGC 4151 was five times as bright today as it was during Astro-1 observations in 1990, and there was a 10 percent increase in brightness today over what we saw when we first observed it two days ago," said Kriss. The galaxy is known to be extremely variable, so Astro-2 scientists hope to view it several more times to capture it at various levels. The multiple pointings should help Hopkins astronomers learn more about the location, composition, density and temperature of the gas. Astro-1 observations of NGC 1068 revealed unanticipated evidence that gas clouds were heated by shock waves speeding from the galaxy's core. Speaking on air-to-ground communication loops from Spacelab Control, Kriss guided Payload Specialist Sam Durrance in placing the telescope's view just outside the core of NGC 1068, to look for the location of the shock-heated gas.

Ultraviolet Imaging Telescope (UIT) team members will search today's photographs of irregular galaxy NGC 4449 for young stars. Active star formation is on-going in these arms, but not in the symmetrical distribution more common in spiral galaxies. The Hopkins telescope focused on a supernova remnant near the galaxy's nucleus, which has a rich store of atomic oxygen buried in a region of ionized hydrogen. While the images should reveal details of star formation regions, spectral measurements of the supernova remnant should show the composition and temperature of the ionized gas.

UIT also photographed an open cluster of hot stars, called N4. These diffuse clusters of stars are thought to be young systems, less than 10 million years old. UIT's wide field of view allows the camera to make ultraviolet images of many stars at a time, so the images will be used to identify hot binary stars pulling matter from one another, planetary nebulae, X-ray sources, white dwarfs and other faint, hot stars.

Other observations today included two white dwarf stars, RE 0512 and GD153; the rapid-star formation galaxy NGC 2903; and another portion of the Cygnus Loop supernova remnant .

On Wednesday, March 8, 1995 at 8 a.m. CST, STS-67 MCC Status Report #12 reports: Astro-2 observations continue, including ultraviolet views of spiral galaxies, the interstellar medium and a very luminous and hot Wolf Rayet star. A successful alignment of the inertial measurement units was performed earlier this morning. Excess water will be dumped through the flash evaporator system today. All consumables are at the appropriate levels at this time in the record-setting mission.

On Wednesday, March 8, 1995 at 4 p.m. CST, STS-67 MCC Status Report #13 reports: Mission Specialist Wendy Lawrence beamed down a video postcard, narrating a tour of the Space Shuttle Endeavour and showing what life aboard is like. The tour included views of the aft flight deck, where astronomical observations are being conducted; the forward flight deck, where shuttle maneuvers are orchestrated; and the middeck, where experiments are studying biotechnology and flexible space structures and the day-to-day activities such as food preparation and personal hygiene are taken care of.

Oswald worked again with the Middeck Active Control Experiment as Gregory took care of orienting the shuttle for its Astro-2 observations and performed housekeeping duties. Grunsfeld and Parise directed the trio of Astro-2 telescopes toward its targets. Gregory and Grunsfeld also conducted an interview with KFWB Radio in Los Angeles.

On Wednesday, March 8, 1995 at 6 a.m. CST, STS-67 Payload Status Report #13 reports: (6/5:22 MET) Although payload controllers at Marshall Space Flight Center in Huntsville, Ala., were briefly evacuated to a safe area during severe weather conditions last night, voice communications with the Shuttle continued from Marshall, allowing Mission Specialist John Grunsfeld to coordinate his activities with science teams on the ground .

Grunsfeld pointed the Astro-2 telescopes at a quasi-stellar object, a prime target for the Hopkins Ultraviolet Telescope (HUT), known as HS1700+64. Principal Investigator Dr. Arthur Davidsen and the HUT science team are searching for the helium left over from the primordial fireball that many scientists believe marked the birth of the universe some 10 to 20 billion years ago. To find the ash remnants of the explosive genesis of the universe, astronomers must use the faint glow of extremely distant objects, such as this quasar, located behind the intergalactic gas similar to using a distant flashlight shining through a hazy mist. HUT was aimed at this Astro-2 target, located many billions of light years away, to help scientists search the gas for evidence that helium is absorbing the quasar's ultraviolet light.

Jernigan and Durrance aligned the Wisconsin Ultraviolet Photo- Polarimeter Experiment (WUPPE) telescope to look at two other stars serving as background lights in the study of interstellar polarization the orientation of ultraviolet light waves that travel through the gas and dust between stars. Interstellar polarization studies enable scientists to make allowances for obscuring matter when they study other objects in the universe as well as learn about the obscuring matter itself.

The Ultraviolet Imaging Telescope (UIT), WUPPE and HUT observed the dying remains of a star a white dwarf. This small object, which has burned all its nuclear fuel, allowed WUPPE Principal Investigator Dr. Arthur Code to observe the orientation of the ultraviolet light traveling from the white dwarf to determine its geometry and density. UIT imaged the white dwarf and the surrounding night sky to help scientists search for more of these faint, hot stars.

Gregory maneuvered Endeavour into position during two separate orbits to allow all three Astro-2 ultraviolet telescopes to observe spiral galaxies. One of these spiral galaxies, known as NGC 2841, contains remnants from Supernovae 1912 and 1957A. The second spiral galaxy, called NGC 2403, is a galaxy containing an old yellow star population in its center region that merges into a disc with widely scattered blue star-formation knots in its spiraling "arms." Guest Investigator Dr. Wendy Freedman will use UIT images of these two galaxies in a digital atlas of spiral galaxies.

Two other galaxies were observed by the ultraviolet telescopes nestled in Endeavour's payload bay last night. Guest Investigator Dr. Claus Leitherer used HUT to observe a starburst galaxy and UIT Principal Investigator Theodore Stecher conducted ultraviolet studies of the structure of galaxies during an observation of elliptical galaxy NGC 205.

During four separate orbits, Jernigan and Durrance pointed the three ultraviolet telescopes toward a rare type of star known as a Wolf-Rayet star. This type of star is thought to represent one of the last phases in the life cycle of a massive star. Wolf-Rayet stars have powerful, eroding stellar winds. These strong stellar winds have hastened the evolution of the Wolf-Rayet stars, causing what may once have been massive, luminous stars to become less and less massive throughout their life. "We are looking at the way energy coming out of the star interacts with the atmosphere surrounding the star," explained WUPPE Co-Investigator Dr. Chris Anderson.

Jernigan and Durrance also brought the Astro-2 telescopes into alignment with two very hot, massive blue stars that emit large amounts of ultraviolet radiation. There is evidence that the outer layers of these two rapidly spinning stars have been peeled off by their stellar winds. From the data gathered during Astro-2, HUT scientists will strive to determine accurate temperatures of these stars to learn more about their surrounding atmosphere, search for stellar winds, and study absorption in the gas and dust between the stars.

On Wednesday, March 8, 1995 at 6 p.m. CST, STS-67 Payload Status Report #14 reports:(6/17:22 MET) The Hopkins Ultraviolet Telescope (HUT) team led the observation of U Geminorum and SS Cygni, two dwarf novas which were also observed during Astro-1. A a dwarf nova, a particular type of cataclysmic variable star, is actually made up of two stars -- a "normal" star like our sun in extremely close orbit with a dense white dwarf. Interaction of the two creates periodic outbursts.

This morning, U Geminorum was at a different phase than it was during Astro-1, when it had just gone through an outburst. "After the outburst, the white dwarf was very hot. Today, the white dwarf was much cooler, since it has been a long time since U Geminorum's last outburst," said HUT Principal Investigator Dr. Arthur Davidsen.

Though SS Cygni was also at quiet stage today, it looked totally different from more typical dwarf novas like U Geminorum. "We could tell SS Cygni is unusual based on our limited Astro-1 observation, but today's much better data reinforces that," said Davidsen. "Normally, the white dwarf is obvious at the center of a cataclysmic variable, but the spectrum from SS Cygni doesn't look like a white dwarf. Instead of seeing light distributed across the spectrum the way we would with a dense star, we see pronounced emission lines that suggest something like a thin, transparent gas disk may surround the dwarf." Davidsen said a disk of gas is created during a hot outburst, but it generally dissipates when a variable is quiet. HUT team members will analyze today's data to help determine what makes SS Cygni apparently unique.

Members of the American Association of Variable Star Observers and amateur astronomers all over the world are monitoring variable stars in both hemispheres 24 hours a day. They furnish regular reports via electronic mail to the Astro-2 experiment teams, so exploding stars can be added to the mission's observation schedule.

HUT also observed V 1329 Cygni, a closely orbiting set of stars with widely different temperatures called a symbiotic star system. Dr. Brian Espey will use far-ultraviolet spectra obtained by the Hopkins instrument to help determine the temperature of the hot star component.

The Ultraviolet Imaging Telescope (UIT) team chose two galaxies for wide-field ultraviolet photography. The first was M 49, the largest elliptical galaxy in the Virgo cluster of galaxies. At twice the size of our Milky Way and ten times more mass, M 49 is one of the biggest galaxies in the nearby universe. "We are interested in trying to trace the source in these galaxies of strong ultraviolet emissions, which were first detected by Dr. Art Code [WUPPE principal investigator] about 20 years ago," said UIT Co-Investigator Dr. Robert O'Connell. "We still don't understand where they are coming from." Astro-1 observations of elliptical galaxies called into question some previously popular theories about the source of the ultraviolet radiation.

UIT also obtained images of M 104, a spiral galaxy viewed edge-on from Earth. M 104 is sometimes called the Sombrero Galaxy because it resembles the shape of a wide-brimmed hat. "The regions where star formation occurs are in the 'brim' of the hat, while the large bulge -- the hat's 'crown' -- is made up of old stars, maybe even a black hole," said UIT Guest Investigator Dr. Barry Madore, who operates what may be the world's largest computerized electronic database of galaxies for NASA at Caltech. "Very old blue stars put out radiation in a glowing halo that surrounds the hat shape," Madore added. These halos had not been imaged in the ultraviolet before Astro-1. Studies of 47 Tucanae, a globular cluster chosen by UIT for study, could shed new light on stellar aging, since some stars within such closely grouped associations seem to age differently than those found elsewhere in our galaxy.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) team concentrated on very hot individual stars for their observation choices today. The instrument made spectral and polarimetric measurements of Zeta Tauri and 28 Tauri, two Oe/Be stars in the constellation Taurus which show bright hydrogen emission lines. The WUPPE team also selected supergiant stars P Cygni and AG Carinae. Massive stars like these process helium and hydrogen into heavier elements, and recycle material into the interstellar medium through supernova explosions and stellar winds.

Light from both types of stars is scattered by various processes in their atmospheres, creating pronounced polarization. However, WUPPE observations of both star types during Astro-1 showed ultraviolet polarization that was different from theoretical predictions. Astro 2 observations will provide data against which to test refined theories. The WUPPE team also completed a series of observations of Wolf-Rayet star HD 96548, in another study of how stars deposit matter containing processed elements like oxygen, nitrogen and carbon into the interstellar medium.

On Thursday, March 9, 1995 at 6 a.m. CST, STS-67 Payload Status Report #15 reports: (7/5:22 MET) Mission Specialist Wendy Lawrence maneuvered the Space Shuttle Endeavour into a position where Payload Commander Tammy Jernigan could align the Ultraviolet Imaging Telescope (UIT) with M33, a nearby spiral galaxy in the constellation Triangulum. This galaxy, also called the Pinwheel galaxy, is approximately 2.4 million light years away, but is bright enough to be seen with binoculars at night. "We are looking at this neighboring spiral galaxy during Astro-2 to learn more about what goes on in that galaxy and compare this information to what we already know about the Milky Way," said Mission Scientist Dr. John Horack.

Payload Specialist Ron Parise aligned the three onboard telescopes, allowing UIT to make deep, wide-field images of a globular cluster of stars known as NGC 362. Globular clusters, massive spherical concentrations of extremely old stars, are generally located outside the plane of the galaxy and form a halo around the center. These old stars (possibly 10 billion years old) provide astronomers with knowledge about the latter part of stellar evolution.

Another type of star cluster, an open cluster, was imaged by UIT last night. An open star cluster is moderate in size, containing from only a few dozen to a few hundred stars. The age of the stars in an open cluster can range from very young stars to older stars. UIT scientists are particularly interested in searching the heavens for white dwarfs and other faint, hot stars to be used as backlighting to study interstellar medium Ð the gas and dust between stars. These data will also provide highly accurate distance measurements and add to astronomers' understanding of the chemical evolution of galaxies.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) telescope examined a supergiant, one of the largest, most radiant stars in the sky. The largest of these massive stars may measure 1,000 times the radius of the sun, but their enormous size is coupled with their voracious consumption of nuclear fuel, leading supergiant stars through speedy evolutions and spectacular deaths in the form of stellar explosions called supernovae.

The three Astro-2 ultraviolet telescopes were pointed at Jupiter's moon Io, the most volcanically active body in our solar system. A recent volcanic eruption on that moon, just before the Astro-2 mission began, ejected material onto Io's surface and into Io's atmosphere. Dr. Paul Feldman, co-investigator for the Hopkins Ultraviolet Telescope (HUT) observed Io last night to detect possible changes in the number of sulfur and oxygen ions in Io's atmosphere. As Io orbits Jupiter once every 42 hours, some of this material is left behind, forming a donut-shaped torus of sulfur and oxygen plasma around Io's orbit. This plasma torus will be observed in a separate Jupiter pointing during Astro-2.

Parise next pointed HUT at a starburst galaxy. While most galaxies appear to have developed their stars billions of years ago, some are forming new stars at an enormous rate in a process known as a starburst. The massive, hot young stars emit strong ultraviolet light, detectable by the telescopes onboard the Space Shuttle Endeavour.

Parise also aligned HUT to observe WX Hydri, a dwarf nova in a binary star system. The dwarf nova for this observation, WX Hydri, undergoes irregularly spaced outbursts, approximately once every 10 days. Scientists for HUT and WUPPE are interested in a process associated with binary stars called accretion, where matter is transferred from the smaller star to the larger star, causing the interstellar gas to heat up and create bright ultraviolet emissions.

HUT observed a very hot, massive blue star for Guest Investigator Dr. Nolan Walborn. The star known as NGC 346 #3 is located in a cluster of stars in the Small Magellanic Cloud. This star is being studied because of its strong stellar winds. Data from this Astro-2 observation will be combined with observations made by the Hubble Space Telescope and the European Southern Observatory's CASPEC satellite, giving scientists a better understanding of this star, which has a relatively brief life from 3 to 6 million years. Several other stars in the NG 346 cluster will also be observed during Astro-2.

On Thursday, March 9, 1995 at 8 a.m. CST, STS-67 MCC Status Report #14 reports: Looking out of the Shuttle's window, Wendy Lawrence recorded volcanic activity on an island south of Burma and replayed the brief video at about 5:45 a.m. CST. An alignment of the inertial measurement units and a water dump through the flash evaporator system were successfully performed this morning. Earlier this morning Commander Stephen Oswald downlinked video of the Middeck Active Control Experiment showing the effects of vibrations on spacecraft. Through this experiment, researchers want to learn how to actively control flexible structures in space. Lawrence continued maneuvering the orbiter while Jernigan and Sam Durrance continued the Astro-2 observations of the ultraviolet universe.

On Thursday, March 9, 1995 at 5 p.m. CST, STS-67 MCC Status Report #15 reports: Oswald worked with the Middeck Active Control Experiment as Gregory pointed the shuttle so that the payload bay telescopes could acquire their targets. Gregory also flew another simulation on the PILOT landing trainer. Grunsfeld and Parise directed the trio of Astro-2 telescopes toward its targets. Oswald, Grunsfeld and Gregory were interviewed by Glen Farley of KING-TV in Seattle at 4:30 p.m.

On Thursday, March 9, 1995 at 6 p.m. CST, STS-67 Payload Status Report #16 reports: (7/17:22 MET) The Astro-2 observatory teamed up with NASA's Hubble Space Telescope today for a close examination of the planet Jupiter's "northern lights." Though Jupiter is always in daylight from Earth's perspective, ultraviolet photographs reveal a glowing circle of charged particles in its upper atmosphere, comparable to the beautiful aurora borealis visible in our far northern latitudes. Payload Specialist Sam Durrance, whose astronomical specialty is Jupiter, carefully centered the Hopkins Ultraviolet Telescope's (HUT) view on the northern region of the planet. The Astro telescopes made high-quality spectral and polarimetric measurements, as well as wide-field, far- ultraviolet images. At the same time, Hubble's Wide Field/Planetary Camera 2 obtained high resolution, far-ultraviolet images of the auroral region. Dr. Paul Feldman, professor of physics at The Johns Hopkins University, is the lead scientist for both the HUT and Hubble observations.

"We're very interested in whether the recent volcanic eruption on Jupiter's moon Io produced more ions in the planet's magnetosphere and led to a brighter aurora. There is some debate as to whether atmospheric ionization in the Jovian system is created primarily by sunlight, as it is in Earth's atmosphere, or by volcanic activity on Io," said Feldman. "We obtained a very nice spectrum of molecular hydrogen, the dominant component of Jupiter's upper atmosphere, which we will analyze in correlation with the Hubble images. By combining the two, we will get a scientific product that is greater than the sum of the two individual observations."

Several of today's observations were for scientific programs designed by Astro-2 guest investigators. As mission planning began, NASA invited astronomers to suggest experiments and observations that could be conducted using one or more of the ultraviolet telescopes. A committee of astronomers reviewed the proposals and selected ten to be included in the observation schedule.

Dr. John Raymond, of the Smithsonian Institution Astrophysical Observatory, used the Hopkins telescope to view two supernova remnants, the Cygnus Loop and Vela F. Both are relatively nearby, with little foreground matter to block a clear view. Raymond is studying the products of supernova explosions -- outwardly moving shock waves containing more energy than most galaxies radiate in a year. As the shock wave and debris from the explosion moves outward, it heats the interstellar medium in its path and may trigger the formation of new stars rich with the elements ejected in the explosion. Scattered long ago by these immense blasts, some of the iron and other heavy elements helped form the world in which we live.

Dr. Claus Leitherer, from the Space Telescope Science Institute, took spectral measurements of the starburst galaxy 1050+40, one where rapid star formation is taking place. Leitherer's colleague, Dr. Nolan Walborn, viewed O-type star SK-61837 in the Large Magellanic Cloud, the nearest galaxy to our own Milky Way. Walborn is studying O stars, the hottest and most massive of the "normal" stars, in a far-ultraviolet portion of the spectrum where they had not been studies previously. Both Leitherer and Walborn used the Hopkins telescope for their investigations.

Guest Investigator Dr. Gregory Bothun, of the University of Oregon, used the Ultraviolet Imaging Telescope (UIT) to observe galaxy VCC 530, one of a recently recognized class of astronomical objects. "They are called "low- surface-brightness" galaxies because they are fainter than the dark night sky. It has only been in recent years, with improvements in telescopes, that we have been able to detect them," said Dr. Barry Madore, another UIT guest investigator. "The most fascinating thing about this class of galaxies is that ground-based observations show some of them are blue. This could be due to an absence of dust, or because they are made up of very metal-poor stars, or maybe they are a new type we're not been aware of before. By viewing them in ultraviolet light, we can get a better understanding of where they came from and what their properties are."

UIT Principal Investigator Ted Stecher, of the Goddard Space Flight Center, chose a cluster of galaxies known as Abell 1367 for observation. The galaxies in this cluster are primarily spirals, like our own Milky Way. Examining photographs of spiral-rich clusters gives astronomers a better understanding of the spatial structure and development of spiral galaxies. UIT made images of Abell 1367 during Astro 1 as well. Stecher also selected NGC 6946, a rapid- star-formation galaxy. Ultraviolet radiation emphasizes the hot stars and dust features associated with spiral arms and suppresses the cool star background of the galactic bulge and underlying disc.

Other observations today spanned the life cycle of stars, from studies of the elderly Schweizer-Middleditch white dwarf star to another search for intergalactic helium left over from the birth of the universe. The Astro telescopes are currently in the midst of a nearly four-hour-long observation series to study the magnetic cataclysmic variable binary star, AM Herculis.

On Friday, March 10, 1995 at 6 a.m. CST, STS-67 Payload Status Report #17 reports: (8/5:22 MET) Payload Specialist Ronald Parise pointed the Hopkins Ultraviolet Telescope (HUT) at a binary star system called AM Herculis. This star system has a white dwarf and a normal low-mass companion star, locked in a tight orbit around each other. As these two stars move around each other, material from the low-mass star is transferred to the white dwarf. During this transfer, matter from the companion star is heated as it spirals down onto the white dwarf, generating a great deal of ultraviolet emission. Because of these outbursts (which may occur every couple of weeks to months or years), binary star systems such as these are called cataclysmic variables.

Several Astro-2 observations have been made of the AM Herculis binary star system because of its unique characteristics. In this star system, the white dwarf star has a strong magnetic field. As material from the companion star is being transferred, the magnetic field of the white dwarf causes the matter to assemble around its magnetic poles. HUT astronomers are using observations of cataclysmic variables during this mission to learn more about how the magnetic transfer of matter differs from the normal transfer of matter between binary stars. In another study of cataclysmic variables, HUT observed EM Cygni, a dwarf nova which has no magnetic field.

During the night portion of two separate orbits, Pilot William Gregory maneuvered Endeavour into the proper orbital position for Parise to align HUT for observations of quasar 1700+64. HUT scientists are using this quasar, located in the constellation Draco, to search the vast region of space between distant galaxies for evidence of helium left over from the primordial fireball that many scientists believe marked the birth of the universe. HUT Principal Investigator Dr. Arthur Davidsen is using the light from this extremely distant quasar as back lighting to shine through the intergalactic medium. Astronomers will use data from these Astro-2 observations to verify recent findings from the Hubble Space Telescope as well as measure the density and ionization state of the intergalactic helium.

Parise also aligned HUT with two white dwarf stars for a study by HUT Guest Investigator Dr. David Finley. White dwarfs are one of the extremely dense remnants of normal stars like the sun. Those being studied with HUT are young and extremely hot stars. Finley is using these HUT observations to get very accurate measurements of the temperatures and surface gravity of white dwarf stars and determine the properties of hydrogen under conditions of extreme temperature and pressure.

Another HUT investigation looked at a portion of a supernova remnant called the Cygnus Loop. Guest Investigator Dr. John Raymond observed this "middle-aged" supernova remnant to study the physics of collisionless shocks, the destruction of grains in shocked gas, instabilities behind radiative shocks, and shock wave parameters.

Parise aimed HUT at Jupiter's moon Io again last night. A recent volcanic eruption on Io ejected material into Io's atmosphere and onto its surface. HUT scientists are observing Io to detect changes in the number of sulfur and oxygen ions in its atmosphere as a result of the volcanic eruption.

The Ultraviolet Imaging Telescope (UIT) imaged two globular clusters last night a metal-poor cluster and a metal-rich cluster. The metal-poor globular cluster, known as NGC 2808, is made up of relatively old stars. The low metal content of these stars indicates they were formed early in the life of the Milky Way galaxy. Astronomers theorize that the metal-rich globular cluster, called 47 Tucanae, once belonged to a small metal-rich galaxy that was swallowed up by the Milky Way in the remote past. The UIT science team will use images from these two types of globular clusters to search for hot binaries that are transferring matter from the massive star to its low-mass companion (accretion), hot white dwarfs, planetary nebulae, and objects associated with X-ray sources in globular clusters.

Payload Specialist Sam Durrance pointed the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) telescope at a young stellar object, still forming out of interstellar dust. WUPPE astronomers will analyze data about the polarization of the ultraviolet light in this object to learn more about the star- formation processes taking place there.

WUPPE scientists also gathered data about hot stars with bright emission lines last night. Principal Investigator Dr. Arthur Code will use information about the orientation of light waves traveling through the circumstellar disk of this star, called 48 Persei, to understand more about the material around it. Although this type of star was first noted because of bright emission lines, over 100 years of study have shown stars like these to be unusual in many other respects. Each spectral region studied provides astronomers with information about a different part of the material around the star.

On Friday, March 10, 1995 at 5 p.m. CST, STS-67 MCC Status Report #17 reports: Commander Steve Oswald conducted more work with the Middeck Active Control Experiment, the MACE device, which is collecting engineering data about the effect of vibrations on free-floating structures. Pilot Bill Gregory spent some time answering questions sent by computer users on the Internet regarding Endeavour's astronomy mission. Hundreds of thousands of questions have been placed on the Internet since the start of the mission, prompting the astronauts to respond when time permits.

On Friday, March 10, 1995 at 6 p.m. CST, STS-67 Payload Status Report #18 reports: (8/17:22 MET) The Ultraviolet Imaging Telescope (UIT) team selected the spiral galaxy M 31, better known as the Andromeda galaxy, for observation. The team is mapping groups of hot, bright young stars, called OB associations, to learn more about star formation within the galaxy. Today's observation concentrated on the northern portion of Andromeda, where its brightest OB associations are located. "We mapped the OB associations in the southern portion of M 31 during Astro 1, and our goal on Astro 2 is to complete the picture," said UIT observing team member Barbara Pfarr. At twice the apparent size of our full moon, Andromeda is too big to be photographed in one frame even with UIT's wide field of view. M 31 is roughly the same size as the Milky Way, and it is the nearest galaxy of comparable size to our own.

Astro scientists also observed NGC 4631, a large spiral galaxy viewed edge-on. The galaxy is forming stars out of material it is pulling from the disk of a nearby, less massive elliptical galaxy, NGC 4656. The bridge of material it is pulling from its smaller neighbor forms a "tail" on NGC 4631. NGC 4631 is of special interest to UIT and Hopkins Ultraviolet Telescope team members because huge loops and filaments of gas have been thrown above and below the galaxy's central region. Astronomers believe this may be a bubble of gas produced by supernova explosions, with very strong stellar winds blowing material out of the galaxy. HUT will use its far-ultraviolet spectrometer to see if there is hotter gas present -- about 200,000 degrees Fahrenheit (100,000 degrees Celsius) or more -- than has been detected in observations by other telescopes.

UIT's ultraviolet images of NGC 4631 will be used to determine how stellar populations are distributed in the galaxy. In addition, they will compare photographs made in different wavelengths with various camera filters to help determine the location of the hot gas, its temperature profile, and its distance from the galactic disk. "We will try to deduce processes by which the gas is heated and cooled, then drops back into the disk," said UIT team member Dr. Andrew M. Smith, "It is theorized that there is a circulation pattern in the gas which is quite large and quite turbulent."

The Hercules Cluster of galaxies, also viewed by the Astro telescopes today, furnishes another laboratory for the study of star formation. Galaxy clusters are the largest gravitationally bound groupings in the universe. Such clusters generally contain both elliptical galaxies, which contain few new stars, and spiral galaxies, which contain many young, ultraviolet-bright stars. The Hercules cluster has a greater than average number of spirals, which makes it a good "hunting ground" for new star formation.

UIT also led observations of two objects near the end of the stellar life cycle, globular clusters NGC 6752 and M 13. Stars within these tightly bound clusters appear to be about five billion years older than recent evidence suggests the universe itself may be -- something like the children being older than the parents. Ultraviolet studies of old stars within the clusters, near the very end of their lives, could provide better tests for the ages and life cycles of stars.

This morning's study of dwarf nova WX Hydri is the second observation of this system, whose decline from outburst is being studied. Though these periodic increases in brightness in WX Hydri are not as bright as they are in some cataclysmic variable systems, they occur fairly frequently -- about once every ten days. WX Hydri sometimes becomes over eight times brighter during an outburst, increasing from a magnitude of about 14.8 during quiet periods to around 11 at its brightest. Information about this dwarf nova and about 10 others is being provided to Astro scientists by amateur astronomers around the world.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) team finished up one period as prime instrument early this morning, then began another after this afternoon's orbiter water dump. This morning, WUPPE looked at reflection nebula NGC 7023. The first prime observation for WUPPE this afternoon was HD 207198, an interstellar polarization probe. Both were studies clouds of gas and material from which astronomers can learn about the interstellar medium -- the material from which stars and other objects are created.

Other celestial objects viewed by the Astro telescopes today included the brightest known Seyfert galaxy, NGC 4151; the Carina dwarf galaxy; spiral galaxy NGC 4258; and NGC 752, an open star cluster in the constellation Andromeda.

On Saturday, March 11, 1995 at 6 a.m. CST, STS-67 Payload Status Report #19 reports: (9/5:22 MET) Pilot William Gregory maneuvered the Endeavour into a position where Mission Specialist John Grunsfeld and Payload Specialist Ronald Parise could align the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) with Nova Centauri 1995. "The WUPPE instrument has given us some spectacular spectral 'signatures' of the elements (such as carbon, nitrogen or oxygen) that may be present in the atmosphere following this very recent explosion," said Guest Investigator Dr. Joni Johnson of the University of Wisconsin in Madison. "We'll be analyzing these data for quite some time, looking for clues about the atmospheric composition, as well as the structure, of this new nova."

Nova Centauri 1995, which occurred just two weeks before the launch of Astro-2, is the result of a Red Giant, transferring material to a compact white dwarf companion star. After a period of time (perhaps 1,000 years or more) the material which accreted onto this white dwarf reached extremely high temperatures and pressure, causing a thermonuclear explosion. WUPPE scientists were excited to be able to observe this rare new nova so soon after its beginning.

Parise also pointed the WUPPE telescope to a massive star that is known to have bright emission lines. Scientists are studying this type of star to learn more about the composition of material surrounding the star and how it is effected by stellar winds.

WUPPE scientists also got another look at a rare Wolf-Rayet star overnight. Wolf-Rayet stars are thought to represent one of the final phases in the evolution of massive stars. This type of massive star has powerful, eroding stellar winds carrying material outward. The interaction between the star's light and this material causes the radiation to be polarized (oriented in one particular direction) rather than in all different directions. The polarization of light coming from this Wolf-Rayet star can tell astronomers something about the properties of the stellar winds around it.

Mission Specialist Wendy Lawrence maneuvered the orbiter to different positions last night, allowing the WUPPE science team to observe two galaxies in the Local Group. Payload Commander Tammy Jernigan operated the Instrument Pointing System, while Payload Specialist Sam Durrance aimed the Astro-2 telescopes at the galaxies. These two galaxies served as background lights for the study of interstellar polarization, the direction that light travels between stars.

The Ultraviolet Imaging Telescope (UIT) imaged Holmberg 2 (a dwarf galaxy) and a portion of the Andromeda spiral galaxy, M31, to help UIT astronomers learn more about young stellar formations in galaxies. One of the major science goals of the UIT is to map out our "twin sister" galaxy, Andromeda (M31). UIT also imaged a galaxy known as NGC 3310, allowing investigators to study the design of spiral galaxies and related structures, the nature of stellar populations, and learn more about the material between stars associated with bars, irregular, and anemic (poor in structure) galaxies.

The Hopkins Ultraviolet Telescope (HUT) observed two Seyfert 1 galaxies, Markarian 279 and NGC 3516. These targets are active galaxies with bright, compact nuclei, radiating in wavelength ranges from infrared to X- ray. HUT Project Scientist Dr. Gerard Kriss arranged simultaneous X-ray observations of NGC 3516 using the Japanese X-ray satellite ASCA (the Advanced Satellite for Cosmology and Astrophysics). Astro-2 and ASCA will revisit NGC 3516 for another observation in two days. UIT scientists observed these galaxies to better understand how energy is transferred between the nuclei and surrounding regions.

Parise pointed HUT at a dwarf nova called Z Camelopardalis (Z CAM). This stellar system has two stars locked in a tight orbit around each other, with an orbital period of seven hours. The companion star to Z CAM is a low mass star which transfers matter onto Z CAM, causing outbursts of ultraviolet emissions.

Parise aligned HUT with a portion of the supernova remnant Cygnus Loop D. HUT scientists are studying a very bright, radiative filament on the western edge of the Cygnus Loop, to learn more about the shock waves generated during the death of a star. Astronomers will analyze these HUT data to determine temperatures, densities, and chemical compositions of the gaseous filaments in the interstellar medium.

On Saturday, March 11, 1995 at 6 p.m. CST, STS-67 Payload Status Report #20 reports: ( 9/17:22 MET) On the tenth day of the STS-67 mission, Astro-2 scientists took their first look in the extreme ultraviolet at what may be the most massive star in the known universe. They also focused their observations on spiral galaxies, elliptical galaxies, and star clusters.

HD 269810, a faint O-class star located in the Large Magellanic Cloud, is about 190 times as massive as Earth's sun and qualifies as a candidate for the most massive star ever observed. Hopkins Ultraviolet Telescope Guest Investigator Dr. Nolan R. Walborn, of the Space Telescope Science Institute, used the HUT instrument to study the star's unusually powerful stellar wind, or expanding outer layer, like it has never been seen before. Although this star probably possesses the most mass a star can have, its stellar wind is depleting this mass at an accelerated rate. These observations provide crucial information regarding the ultimate fate of the most massive stars.

Dr. Walborn uses the HUT to study a sample of very hot O class stars that are currently being observed in ultraviolet wavelengths of 1200 angstroms and above by the Hubble Space Telescope. However, only HUT is able to take its unprecedented measurements of these stars in the 900-1200 angstrom wavelength range. Commenting on what he called the "beautiful" real-time data acquired from this observation, Dr. Walborn said, "Now we have new information about a current candidate for the most massive star known. This was the star I wanted to see, and now we have it."

Earlier this morning, Payload Specialist Sam Durrance successfully pointed the Astro telescopes at a somewhat challenging target, the elliptical galaxy M60, to enable the science teams to obtain an overall average spectrum of stars in its core. A roughly sphere-shaped galaxy with no clearly discernible internal structure, M60 contains older, evolved stars and therefore represents a stable stage of development. Due to the faintness of this galaxy and the absence of suitable guide stars for automatic targeting, manual acquisition of this target was necessary.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) also observed the center of the M60 giant elliptical for polarized radiation, or radiation preferentially oriented in one direction. M60 is part of rich cluster of galaxies in the Virgo constellation, containing about 2500 galaxies, and has a notable ultraviolet excess.

The Ultraviolet Imaging Telescope (UIT) viewed NGC 6791, an unusual open cluster located 14,000 light years away in the Lyra constellation. Open clusters are diffuse collections of 100 to 1,000 stars and are usually thought to be young systems, less than 10 million years old. As one of the oldest known open clusters, NGC 6791 is three billion years older than our solar system. Because UIT's field of view is well matched to the sizes of these clusters, UIT scientists are able to perform ultraviolet observations of many stars at the same time.

Another target for UIT, M101 in the Ursa Major constellation, was a big spiral galaxy with arms that are wide and not very tightly wound. A perfect example, or prototype, of spiral structure, it is the highest priority spiral galaxy for UIT. This galaxy contains bright regions, such as Searle 2 (named for Dr. Leonard Searle, the astronomer who first discovered that region), of glowing hydrogen ionized by hot blue stars. UIT's ultraviolet imaging offers a powerful new tool for the study of these regions, especially since it emphasizes these hot stars. Ultraviolet imaging also suppresses the cool star background of the galaxy, allowing the young hot stars to become more evident to astronomers studying the evolution of stars.

On Saturday, March 11 1995 at 5 p.m. CST, STS-67 MCC Status Report #19 reports: Gregory continued work with the Portable In-Flight Landing Operations Trainer, PILOT, a laptop computer and hand controller designed to simulate Shuttle landings. The device helps Shuttle Commanders and Pilots to stay sharp during long duration flights.

On Sunday, March 12, 1995 at 9:30 a.m. CST, STS-67 MCC Status Report #20 reports: Tammy Jernigan, Sam Durrance and Wendy Lawrence assisted ground controllers in Alabama with fine-pointing of the three telescopes. For the first time, an observation was made of the Moon as the Shuttle passed south of Hawaii on the 161st orbit of the mission in an effort to gather ultraviolet data to help determine the Moon's origin. Several additional observations of moons and asteroids will be made throughout the mission.

On Sunday, March 12, 1995 at 6 a.m. CST, STS-67 Payload Status Report #21 reports: (10/5:22 MET) Mission Specialist Wendy Lawrence maneuvered the orbiter into the required position, while Payload Commander Tammy Jernigan aligned the Instrument Pointing System (IPS) at the most difficult-to-acquire Astro-2 target, our moon. Payload Specialist Sam Durrance coordinated with science teams at Marshall Space Flight Center in Huntsville, Ala., to accurately point the Ultraviolet Imaging Telescope (UIT) at the moon. "The entire moon has never been imaged in the ultraviolet wavelengths, and we're looking forward to seeing these data," said UIT Guest Investigator Dr. Chan Na of Southwest Research Institute. No similar data have been obtained from either previous Shuttle missions, the Apollo program or Clementine, and there are no operating or planned spacecraft capable of imaging the whole moon at far ultraviolet wavelengths.

UIT Guest Investigator Dr. Randy Gladstone, also of Southwest Research Institute, is using UIT to make far ultraviolet maps in order to learn more about the surface properties of the moon. "This lunar observation yielded 12 good, wide-field exposures of the moon," said Gladstone. The 70mm UIT film will developed and analyzed when Endeavour returns to Earth. UIT data gathered during Astro-2 will be used to test the hypothesis that the far ultraviolet surface brightness of an object without an atmosphere is a good indicator of the length of time that the surface has been exposed to space. These data will also help scientists understand future ultraviolet images of asteroids and other planetary satellites.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) telescope observed the moon along with UIT last night to determine how well the WUPPE instrument could detect such features as dark seas or bright craters on the moon. Video from the WUPPE guide camera showed the instrument could clearly distinguish these lunar surface features. WUPPE scientists will now decide what observational goals they will set for the next lunar observation, later in the mission.

Durrance also pointed the WUPPE telescope to a cool, giant star known as Alpha Orionis. This star, which pulsates about every five years, is approximately 14,000 times as radiant as our sun. WUPPE Principal Investigator Dr. Arthur Code will analyze the data from this Astro-2 observation to learn more about what effect these pulsations have on the envelope of gas and dust surrounding Alpha Orionis.

Pilot William Gregory moved Endeavour into position, Mission Specialist John Grunsfeld aligned the IPS and Payload Specialist Ronald Parise again pointed the Hopkins Ultraviolet Telescope (HUT) at the quasar known as 1700+64. This quasar is the most distant object the HUT team is observing during Astro-2. HUT Principal Investigator Dr. Arthur Davidsen, of Johns Hopkins University, is using the quasar to provide background lighting in a search for helium in the intergalactic medium (the gas between galaxies). Helium is thought to be left over from the "Big Bang," a primordial fireball that many astronomers believe marked the birth of the universe about 10 to 20 billion years ago.

The HUT telescope also observed a portion of the Cygnus Loop, a "middle-aged" supernova remnant, over night. Supernova remnants are visible evidence of the final cycle of stellar evolution and important sources of information for astronomers. The Cygnus Loop is of particular interest because it reveals details about the structure and velocity of shock waves from the explosion of a dying star) as they travel through the interstellar medium. HUT's spectrographic data will help scientists determine temperatures, densities and chemical compositions of the gases located in the Cygnus Loop.

HUT team members say their recent observations of the Vela supernova remnant will allow scientists, for the first time, to measure the same supernova remnant shockwave from two angles. The Vela observations seem to show the same filament of expanding gas from the stellar explosion both edge on and face on. "If we can compare this filament in two positions, and verify that the models work for this object, we can generalize that and compare it to other data we've taken on the Cygnus Loop, the Vela supernova remnant and with other telescopes," said HUT Co-investigator Dr. Bill Blair. If successful, the comparison should give researchers a much better understanding of supernova remnants.

Parise pointed WUPPE and HUT at a hot, massive star called 48 Librae, located in the constellation Libra. This star spins rapidly and has an outer layer that shows evidence of being peeled off by stellar winds. Previous observations of this star have suggested that its stellar winds are strongest near the star's equator because of its rapid rotation. WUPPE scientists are examining the polarization of this star's light to learn more about the scattering by electrons in the disk surrounding it. HUT scientists are trying to determine an accurate temperature for this star, search for stellar winds, and study absorption in the gas and dust between this star and nearby stellar objects.

Jernigan and Durrance aligned WUPPE and HUT to look at a supergiant star, P Cygni. This star, which increases in brightness like a nova, has remained just visible to the naked eye for more than 100 years. Scientists believe it is not a true nova, rather a variable star surrounded by an expanding gaseous shell. WUPPE scientists are interested in P Cygni because it is ejecting mass at a colossal rate. As P Cygni scatters light, it produces a pronounced polarization which differs from theoretical models. Data from these Astro-2 observations will test refined theories and offer greater insight into the mysterious variability of P Cygni.

Throughout the next 12 hours, HUT, WUPPE and UIT will be used to observe the planet Mars, look at young stellar populations in galaxies, examine supernova remnants and study a reflection nebula in a dark cloud.

On Sunday, March 12, 1995 at 5 p.m. CST, STS-67 MCC Status Report #21 reports: Both Grunsfeld and Parise enjoyed a few hours off to relax before heading into the final days of the mission, trading places on the aft flight deck to operate the Instrument Pointing System and the telescopes while the other took a break from research duties. Gregory used Endeavour's ham radio gear to talk to students at the J.J. Fray Elementary School in Rustburg, Virginia and the crew continued to respond to questions about their mission and spaceflight in general placed on the Internet and faxed up to the Shuttle by flight controllers.

On Sunday, March 12, 1995 at 6 p.m. CST, STS-67 Payload Status Report #22 reports: (10/17:22 MET) The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) team selected Nova Circinus 1995 for observation this morning. This is the third "new" nova -- a binary star system whose first outburst was observed very recently -- to be studied by the Astro-2 telescopes. "Though all three novae went into outburst since the first of the year, each is at a different stage in its history," said WUPPE Principal Investigator Dr. Arthur Code. "By comparing their polarization, we hope to determine whether gas from novae outbursts is expelled in a spherical shape and then becomes more asymmetrical, and if so, how quickly the asymmetry develops." Light is polarized when it encounters an asymmetrically shaped object, such as a flattened gas disk, which causes the light to vibrate in preferred directions.

"Every day brings new surprises," said HUT Co-investigator Dr. Bill Blair, describing the success today of two supernova remnant observations he admits were long-shots. HUT led a study of the supernova remnant Puppis A, the third supernova remnant Astro-2 has observed in our Milky Way galaxy. HUT and WUPPE examined a filament of gas in the remnant's eastern region, apparently an interaction between an interstellar cloud and the blast wave speeding from the supernova explosion. "The International Ultraviolet Explorer barely detected this remnant, so we didn't know what to expect," said Blair. "We thought dust in the interstellar medium might block its ultraviolet radiation, but we got a very nice spectrum which showed strong nitrogen emissions." Blair said it is possible the nitrogen could have been thrown out by the massive star thousands of years before it exploded as a supernova, and now the shock wave from the blast is catching up with nitrogen expelled from the star.

Supernova 1006, whose explosion in A.D. 1006 makes it a relatively recent supernova, provided another first. "The shock wave from this supernova is moving very fast, plowing through interstellar space at about 2,000 kilometers (1,250 miles) per second, as opposed to 150 to 200 kilometers per second in remnants like Puppis A," said Blair. "We thought its emissions might be too faint for us to observe, but we felt it was important enough to attempt. This gives us a new range of velocity that has never been observed before in the ultraviolet." Blair said the HUT spectrum may show the primary passage of the supernova blast wave as it first encounters interstellar gas. Comparison with optical observations could help astronomers understand the basic physics of supernova shock fronts.

The Ultraviolet Imaging Telescope team led eight highly successful observations in a row. UIT captured the mission's first images of the Whirlpool Galaxy (M 51) for Dr. Wendy Freedman's atlas of spiral galaxies. The Whirlpool Galaxy is the larger of two interacting galaxies close enough together to disturb each other through gravitational force. M 51 is a large spiral galaxy with a mass 100 billion times that of our sun. It is interacting with NGC 5195, a much less massive galaxy. Astronomers will study UIT photographs to learn more about the formation of stars in that system, especially in the bridge of matter that joins the two interacting galaxies.

UIT also imaged CB_4, a cold cloud of interstellar gas and dust which is sufficiently dense to obscure starlight from objects behind it, while it reflects light from objects in front of it. Though this so-called dark cloud is relatively faint, Astro scientists were able to obtain measurements to test models of dust in the interstellar medium during a daylight observation.

The imaging telescope also photographed a cluster of galaxies known as the Coma Cluster. UIT is examining the dense cluster, made up primarily of elliptical galaxies, to obtain simultaneous information on large samples of galaxies. Astronomers will study the integrated ultraviolet properties of these large samples to determine constraints on the physics of cooling flows, as hot gas may condense into stars as it rains down on a galaxy from the intra-cluster medium. Scientists also will look for the presence of dark matter, which does not emit appreciable radiation.

HUT and WUPPE observed NGC 4874, the central elliptical galaxy in the Coma Cluster, to determine the ages of its stars. Though elliptical galaxies have comparatively few young stars, they emit more ultraviolet radiation than would be expected from a population of old stars. Astro-1 observations of ellipticals suggest this radiation may come from aging stars in a previously unknown stage of evolution. Astro-2 is following up on the mystery.

UIT photographed the open star cluster NGC 7789, and investigations into new star formation included observations of elliptical galaxy NGC 185, irregular galaxy NGC 1313 and rapid star formation galaxy NGC 4631. WUPPE led the mission's first observation of the Planet Mars, and it observed interstellar polarization probe HD 217490 to add to its ongoing study of the dust scattered throughout our Milky Way. Dr. Brian Espey got excellent HUT and WUPPE data on the symbiotic star system RR Telescopii for his study of closely orbiting stars with radically different temperatures.

On Monday, March 13, 1995 at 8 a.m. CST, STS-67 MCC Status Report #22 reports: Jernigan and Durrance were interviewed by C-SPAN earlier this morning and discussed various aspects of the mission and space flight in general with viewers.

On Monday, March 13, 1995 at 6 a.m. CST, STS-67 Payload Status Report #23 reports: ( 11/5:22 MET) Scientists with the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) received surprising data from their telescope last night as the second Astro Observatory (Astro-2) mission continued aboard the Space Shuttle Endeavour. Astronomers for WUPPE were surprised to learn that the orientation (polarization) of ultraviolet radiation coming from Mars is due to the planet's soil composition, rather than elements in the Martian atmosphere. "As we looked at the data we received from our equipment onboard the Shuttle, we saw similarities between the polarization of ultraviolet light emitted by Mars and the polarization of ultraviolet light recorded during an earlier lunar observation," explained WUPPE scientist Dr. Geoff Fox. "We'll continue to examine our data to learn more about the composition of Martian soil."

The WUPPE telescope also made observations to study the polarization of ultraviolet light between stars in the Large Magellanic Cloud for Guest Investigator Dr. Geoffrey Clayton. Supergiant stars were used as background lighting, allowing WUPPE and the Hopkins Ultraviolet Telescope (HUT) to observe dust particles between stars in this galaxy. WUPPE and HUT science teams expect to see differences in interstellar polarization between the Large Magellanic Cloud and our own Milky Way galaxy because the chemical elements found in the interstellar dust of these galaxies are so different. UIT will collect images of large fields in the Magellanic Clouds during this mission to study stellar mass and age distributions in the galaxy.

HUT observed two Seyfert 1 galaxies in the constellation Ursa Major, the Big Dipper, last night NGC 3516 and NGC 4151. These galaxies, named for astrophysicist Carl Seyfert, are believed to be powered by supermassive black holes at their cores. Spectra of these galaxies show broad emission lines, indicating clouds of gas moving at thousands of miles per second, with the energy emitted covering a broad range of frequencies. HUT scientists are studying variations in the amount of ultraviolet light in these galaxies to learn more about the processes that affect their spectra. The Ultraviolet Imaging Telescope (UIT) also observed these galaxies to help astronomers understand more about the transfer of energy between the nuclei and surrounding regions.

Mission Specialist John Grunsfeld pointed HUT at Venus, the planet that most resembles Earth in size, density and composition. Planetary probes have shown Venus to have an atmosphere largely composed of carbon dioxide, extremely high surface temperatures, constant high surface winds, and atmospheric pressure 90 times that of the Earth's. HUT scientists are searching the atmosphere of Venus for traces of argon, neon and helium. The presence of these gases in Venus' atmosphere are important indicators concerning the formation of the solar system. WUPPE observed Venus to learn more about the polarization properties of the atmosphere surrounding the planet and will use these data to understand more about the polarization of light from Jupiter during an upcoming Astro-2 observation.

Grunsfeld also aligned HUT to observe two pulsating white dwarf stars last night. These two stars, one located in the constellation Hercules and another in Ursa Minor, are believed to be in a transitory stage in the evolution of extremely hot white dwarfs. Astronomers will use information from Astro-2 observations such as this one to learn more about the evolution of stars.

Payload Commander Tammy Jernigan moved the Instrument Pointing System into position for Payload Specialist Sam Durrance to point UIT at celestial objects. The first object, galaxy NGC 4214, was imaged by UIT to be included in an atlas of spiral galaxies being created by Guest Investigator Dr. Wendy Freedman. When completed, this atlas will be available at no cost to the astronomy community through the on-line electronic facilities of the NASA/Infrared Processing and Analysis Center Extragalactic Database.

A deep survey field, known as UGC 5675, was also imaged by UIT last night. UIT Principal Investigator Theodore Stecher will also use these images to learn more about the population of distant non-thermal sources, search for high redshift blue galaxies, determine galactic luminosities for faint magnitudes, identify distant clusters of star-forming galaxies, and obtain counts of galaxies down to faint ultraviolet magnitudes to complement similar data in visual and other spectral regions. UIT Guest Investigator Dr. Gregory Bothun will use images of this dark area of the sky to determine if UIT can detect very faint galaxies against a dark background and search for a bright near-ultraviolet component that may be responsible for extremely blue optical colors that have been observed in other galaxies with very low star-formation rates.

On Monday, March 13, 1995 at 5 p.m. CST, STS-67 MCC Status Report #23 reports: Commander Steve Oswald spent most of the day working in the middeck with the MACE experiment, the Middeck Active Control Experiment, a device rigged with sensors to measure the degree of vibration on free-floating structures. Engineering data from the experiment will be used by technicians in the design of spacecraft of the future. Oswald and Mission Specialist Wendy Lawrence, both graduates of the Naval Academy, joined Payload Specialist Ron Parise to discuss various aspects of the flight with Midshipmen gathered at Annapolis. Lawrence is the first female graduate of the Naval Academy. The in-flight interview also featured greetings to the crew from former astronaut Charles Bolden, who currently serves as the Deputy Commandant at Annapolis.

On Monday, March 13, 1995 at 6 p.m. CST, STS-67 Payload Status Report #24 reports: (11/17:22 MET) Astro-2 observations today ranged from exotic star formations with odd- sounding names to our familiar celestial neighbor, the Planet Venus. Astronomers collected additional information for a variety of investigations which have been in progress throughout the mission.

The Hopkins Ultraviolet Telescope (HUT) team began their block of observations with HH 2H, an object that could be a young star just emerging from the "cocoon" of dust around it. Called Herbig-Haro objects, after the astronomers who discovered them in 1946, these small bright concentrations of dust and gas are believed to be gas jets thrown off during the final evolutionary stages of a protostar, an object that has not collapsed sufficiently to begin the nuclear reactions of a mature star.

The Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) led an observation of another infant star, AB Aurigae. Called a pre-main sequence star, AB Aurigae is part of a class of young stars that are still surrounded by the dust and gas clouds from which they are formed. These envelopes of matter around the objects are highly active, as evidenced by variations of polarization seen in the optical and infrared wavelengths. WUPPE's ultraviolet observations should help astronomers understand how dust is processed during star formation and how material around young stars is distributed.

All three telescopes viewed HUT's choice of Markarian 421, a quasar- like active galaxy nucleus known as a BL Lacertae object. When the first object of this type was identified, in the constellation Lacerta, it was erroneously thought to be a variable star. In the 1960s, astronomers discovered that BL Lac objects are not stars in our Milky Way, but the incredibly more powerful active cores of distant galaxies. Massive black holes are expected to be the power sources for objects in this class. While BL Lac objects produce strong radiation in all observation wavelengths, their radiation is primarily non-thermal -- created not by heat but by the glow of electrons moving at almost the speed of light as they pass through a magnetic field. NASA's Extreme Ultraviolet Explorer satellite discovered strong ultraviolet emission lines in Markarian 421, suggesting it is an excellent subject for HUT's far-ultraviolet studies. Ground-based observations show a high level of polarization in visible light, so WUPPE ultraviolet polarization measurements should provide revealing insights into phenomena in the centers of such galaxies.

The observation of Venus this morning followed up on last night's look at Earth's "twin" planet. HUT studied the planet's forbidding atmosphere -- 100 times denser than Earth's and as hot as 900 degrees Fahrenheit (480 degrees Celsius) -- looking at upper atmosphere gases that are excited by ultraviolet solar radiation. Scientists will compare Astro-2 observations of Venus and Mars to see how the two planetary atmospheres, both primarily carbon dioxide but with radically different densities, respond to ultraviolet radiation from the sun.

Two HUT observations today, NGC 6090 and 0833+652, were for Guest Investigator Dr. Claus Leitherer's study of starburst galaxies. Leitherer hopes to determine whether ionized hydrogen is being released from the galaxies, which put out a great deal of ultraviolet energy due to the rapid star formation taking place within them. "This is another attempt to view the interstellar medium," explained HUT Principal Investigator Dr. Arthur Davidsen. "We feel certain there must be material left over from the formation of the universe, just like there would be flour left on a cutting board after a loaf of bread is kneaded. But we have never been very successful in observing this material." Davidsen said the material might be highly ionized, possibly by quasars or by starburst galaxies, making it difficult to observe. "If we can find out how much ionized hydrogen starburst galaxies are putting out, we can get a good idea how much they emit into interstellar space," Davidsen said. "We may find that these galaxies are an important source of ionized interstellar hydrogen, or it may not be there at all. Either way, we've helped answer an intriguing question."

HUT also led the Astro telescopes in an examination of the planetary nebula nucleus K1-16. Astronomers hope to better understand the chemistry of the nebula and the evolutionary state of its central star. The nebula is unstable, going through periodic pulsations in magnitude and color. While the star's evolutionary status is not clear, astronomers believe it could be on its way to becoming a white dwarf.

The Ultraviolet Imaging Telescope (UIT) team made more images of star groupings to study the life cycles of stars. They photographed Abell 1795 and the Hercules Cluster, both clusters of galaxies where star formation is taking place. The Hercules Cluster is made up primarily of spiral galaxies, whose pinwheel arms are stellar nurseries. Abell 1795 is a galaxy cluster which emits large quantities of X-rays. Gas in the cluster is cooling rapidly and could be producing stars at the rate of 300 solar masses per year. UIT's observation of globular star cluster NGC 6752 focused on the opposite end of stellar evolution. The cluster is tight grouping of relatively old stars whose low metal content indicates formation early in the life of the Milky Way galaxy. UIT also imaged elliptical galaxy M32.

Late this afternoon, the WUPPE team devoted two observations to planned calibrations of their instrument's sensitivity, with HD 161056 serving as a polarized standard and Beta Ursa Majoris as an unpolarized standard.

On Tuesday, March 14, 1995 at 6 a.m. CST, STS-67 Payload Status Report #25 reports: (12/5:22 MET) The Ultraviolet Imaging Telescope (UIT) imaged NGC 2300, a cluster of galaxies that emits large quantities of X-rays. The study of clusters can provide a wealth of information to astronomers. Astro-2 data may provide UIT scientists with a better understanding of the relationship between galaxies in a cluster, the relationships between different levels of clusters and star formation in clusters of galaxies.

UIT also imaged a globular cluster, NGC 5272, that contains relatively old stars. The low metal content in this cluster of stars indicates they were formed early in the life of the Milky Way galaxy. The telescope, image intensifiers and cameras of the UIT instrument are helping astronomers search for hot accreting binaries, hot white dwarfs, planetary nebulae and objects associated with X-ray sources in globular clusters.

The study of young stellar populations in galaxies continued when UIT was pointed at a galaxy field in the spiral galaxy Andromeda. Approximately half of UIT's Astro-2 science program is devoted to the study of star-forming galaxies such as this one. A unique feature of UIT is the identification of thousands of individual hot stars in other galaxies that shine brightly in the ultraviolet. These hot stars may be observed later by the Hubble Space Telescope. UIT imaged another spiral galaxy, NGC 925, to provide images for Guest Investigator Dr. Wendy Freedman's atlas of spiral galaxies.

UIT and the Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) were pointed at the moon again last night. UIT imaged the moon to help astronomers, such as Guest Investigator Dr. Randy Gladstone, learn more about the surface properties of the moon. Scientists will develop and analyze the UIT film after Endeavour returns to Earth to understand future ultraviolet images of asteroids and other planetary satellites. WUPPE scientists observed the moon, looking at the reflection of ultraviolet light for distinctive differences in the maria (dark areas of the lunar surface) and highlands (brighter surface features of the moon).

The Hopkins Ultraviolet Telescope (HUT) was used to observe a radio- loud quasar in the far- and extreme-ultraviolet wavelengths. HUT Principal Investigator Dr. Arthur Davidsen will analyze the Astro-2 data of this quasi- stellar object (located in the constellation Eridanus) to understand more about the shape of its ultraviolet spectrum. Davidsen is looking for the region of the ultraviolet spectrum where the hydrogen becomes opaque to radiation. He will then compare what he learns from these observations with what astronomers already know about the disk-shaped structure of stellar matter surrounding a black hole, testing the theory that quasars are powered by supermassive black holes.

Hopkins scientists also observed the Seyfert galaxy NGC 5548 with HUT last night. The ultraviolet absorption lines in the HUT spectrum will be used in conjunction with earlier X-ray observations to determine the physical conditions in the hot absorbing gas. The absorbing gas in this Seyfert 1 galaxy may be the "reflecting medium" that produces the polarized reflection spectrum seen in Seyfert 2 galaxies such as NGC 1068.

Two elliptical galaxies were also observed by HUT last night. Elliptical galaxies, which are spherical with no clearly defined internal structure, contain older, more evolved stars. Galaxy M87, the central galaxy in the Virgo cluster, shows signs that star formation may be occurring even though elliptical galaxies do not have enough stellar matter for new star formation. Another galaxy, known as M60, is being observed during this mission because it has a very high "ultraviolet upturn" an excess of ultraviolet output for an old star population. The UIT team is also very interested in these targets UIT collected ultraviolet images of both galaxies in support of several science programs.

The WUPPE telescope was calibrated during an observation of Beta- Ursa Majoris, a star that remains relatively constant in luminosity. The surrounding area of this star is virtually dust free, giving WUPPE scientists a good, clear target to determine if there have been any changes in the performance of their telescope during this mission.

HUT and WUPPE scientists used their ultraviolet telescopes to study a binary star system known as a magnetic cataclysmic variable. This two-star system, called AM Herculis, has a white dwarf star that pulls material away from its companion red star. A strong magnetic field on the white dwarf causes stellar material from the red star to accumulate on the white star's poles. Information about the dynamics of mass transfer in a binary star system is important because accretion, or the accumulation of gas, is essential to many astrophysical situations, such as star and planetary formation.

On Tuesday, March 14, 1995 at 8 a.m. CST, STS-67 MCC Status Report #24 reports: Endeavour's crew was notified of the Mir-18 launch shortly after the Soyuz capsule reached orbit. STS-67 Commander Steve Oswald responded, "Okay, great news, thank you very much....Bet you Normie's glad to be there." Oswald and Thagard flew together on Discovery's STS-42 mission in January 1992.

On Tuesday, March 14, 1995 at 5 p.m. CST, STS-67 MCC Status Report #25 reports: Before turning in for an eight-hour sleep period, the Blue team astronauts, Wendy Lawrence, Tammy Jernigan and Sam Durrance, joined their colleagues in the traditional in-flight Crew News Conference, answering questions from correspondents on everything from astronomical research to the symbolism of the launching of U.S. astronaut Norm Thagard on a Russian rocket this morning to begin an historic three-month stay on the Mir Space Station.

Earlier today, NASA's Mission Management Team decided NOT to extend Endeavour's flight beyond Friday's planned landing at the Kennedy Space Center. Citing the wealth of scientific data already acquired by the Shuttle's telescopes and the conservative approach being taken in slowly building up the length of time for orbiting crews, Mission Operations Representative Jeff Bantle said the decision to end Endeavour's journey on time was made after weighing numerous factors regarding a mission extension, both pro and con.

On Tuesday, March 14, 1995 at 6 p.m. CST, STS-67 Payload Status Report #26 reports: CST (12/17:22 MET) The majority of today's Astro-2 observations were of objects in the Large and Small Magellanic Clouds. These irregular galaxies, in the southern hemisphere sky, are satellites of our Milky Way galaxy. They are gravitationally bound with some 20 others that make up our "local group" of galaxies.

The Ultraviolet Imaging Telescope made the mission's first photographs of Supernova 1987A. The February 1987 stellar explosion, in the Large Magellanic Cloud, was the first supernova explosion visible to the naked eye since 1604 A.D., six years before the first telescope was used to view the heavens. The supernova reached its brightest visible radiation level in May 1987, but scientists believe an intense flash of ultraviolet light occurred almost at the moment of the explosion, when the outer layers of the supernova lifted away. UIT is attempting to photograph the light "echo," or reflection of this maximum ultraviolet output, as it bounces off sheets of dust in space. UIT's Astro 1 photographs of Supernova 1987A indicate the echo is extremely faint, so UIT is making a number of long exposures to capture it. "If we see the same phenomenon in several exposures, we can not only add them together to improve the quality of our observations; the repeated evidence assures us that what we are seeing is real," said UIT team member Dr. Steve Maran.

An observation of N 79 looked at young star formation in a Large Magellanic Cloud star grouping called an "OB Association." Unlike other types of star clusters, there is insufficient gravitational attraction to hold these groups of very young, hot O and B stars together. Though formed at the same time, the stars are rapidly drifting apart.

Other targets in UIT's eight-observation time block included two Large Magellanic Cloud open star clusters which are surrounded by emission rings. N 51, in the southern constellation Dorado, is an unusual nebula which appears to be a bubble blown in the interstellar gas by wind from a very massive hot star. The imaging telescope made limited observations of the area during Astro-1, and the science team hopes to collect more extensive data on this flight. N 70, in the southern constellation Hydra, is a region of space where the gas has been ionized. The UIT team will compare images made at two different wavelengths to help determine what caused the ionization.

UIT also photographed the bar structure of the Large Magellanic Cloud, an elongated linear accumulation of stars in the galaxy, as part of its study of young star populations. Dr. John Raymond, of the Smithsonian Institution's Astrophysical Observatory, added to his study of interstellar shock waves with an observation of LMC 519, an old supernova remnant also in the Large Magellanic Cloud. Dr. Nolan R. Walborn got another observation of a hot O star in the open star cluster NGC 346, for his study of the strong stellar winds produced by these stars in the Large and Small Magellanic Clouds.

This evening, Dr. Geoffrey Clayton began another block of observations for his study of interstellar dust in the Large Magellanic Cloud. Wisconsin Ultraviolet Photo-Polarimeter Experiment (WUPPE) Principal Investigator Dr. Arthur Code is researching the sizes and chemical compositions of dust grains in the Milky Way's interstellar medium. Clayton is extending the sample to the nearby Large Magellanic Cloud, where interstellar chemical abundances are known to be quite different from those in our own galaxy.

All three telescopes participated in the third Astro-2 observation of 47 Tucanae, a metal-rich globular cluster in the southern Milky Way. The Astro telescopes also viewed Centaurus A, the nearest active galaxy to our own and one of the most prominent radio sources in the southern hemisphere.

Earlier today, the WUPPE science team selected NGC 3132, a young planetary nebula in the constellation Vela, for observation. A planetary nebula is a bright cloud ejected by the star at its center, believed to be a phase in the life of certain lower mass stars when they expel large amounts of material in to space. Sometimes called the "Eight-Burst" Nebula because its elliptical disk looks like several oval rings superimposed and tilted at different angles, NGC 3132 is one the few planetary nebulae known to have a binary star system at its center. WUPPE scientists will examine the light scattered by dust in the cloud to study the nature of the dust, which will eventually return to the interstellar medium. Ultraviolet Imaging Telescope images will test ionization and temperature levels within the nebula. The Hopkins Ultraviolet Telescope (HUT) took spectra of the cloud itself and of its binary star.

The WUPPE team led the Astro telescopes back to the Nova Aquilae 1995. This was the mission's third look at the nova whose outburst, or sudden increase in brightness, was first observed some three weeks before the STS-67 launch. Successive polarization measurements during Astro-2 will allow WUPPE scientists to look for changes in the shape of the gas disk and for possible clumps ejected during the outburst.

The HUT team chose the quasar 1211+143 as one of their targets today. Team members will study the shape of the quasar's ultraviolet spectrum to learn more about the intrinsic qualities of the quasar itself. First discovered in the 1960s, quasars are the most luminous and energetic, as well as the most distant, objects in the universe. They are believed to be powered by supermassive black holes at their centers. HUT observations will test the current understanding of accretion disks, or disks of matter being whirlpooled and sucked into the black hole.

WUPPE's Large Magellanic Cloud dust study will continue into this evening. UIT has chosen two galaxies and an open star cluster for imaging tonight. The HUT team will lead observations of two quasars, several individual stars, a planetary nebula, an elliptical galaxy, and another supernova remnant.

On Wednesday, March 15, 1995 at 6 a.m. CST, STS-67 Payload Status Report #27 reports: (13/5:22 MET) STS-67 Pilot William Gregory placed the orbiter in the proper attitudes for Mission Specialist John Grunsfeld to align the Instrument Pointing System (IPS) to selected areas in the sky. Payload Specialist Ronald Parise then aligned the Wisconsin Ultraviolet Photo-Polarimeter (WUPPE), the Hopkins Ultraviolet Telescope (HUT) and the Ultraviolet Imaging Telescope (UIT), allowing them to lock on to four targets in the Large Magellanic Cloud (LMC).

Guest Investigator Dr. Geoffrey Clayton of the University of Colorado in Boulder will use WUPPE and HUT information about ultraviolet polarization in the LMC, comparing these data to what scientists already know about the nature of dust particles in the interstellar medium of our own galaxy. Using selected stars of the LMC to back light the dust and gas, Clayton can examine the behavior of the many dust grains found there. In contrast, a bright, blue-hot supergiant star, Sanduleak 67-90, was the target of one of last night's four LMC observations to let astronomers study the dynamics of ultraviolet emissions in an area where there was not a substantial amount of stellar dust. UIT takes images of all fields in the Magellanic Clouds, and obtained excellent data in parallel with the observations being made by HUT and WUPPE.

In other observations over night, HUT scientists got another chance to learn more about a halo of ultra-hot gases they believe surrounds our Milky Way galaxy. HUT was pointed at the brightest quasar in the sky, 3C273, which is approximately two billion light years away. As ultraviolet light from the quasar shines through interstellar space, it is absorbed by the halo that surrounds our galaxy. Scientists at the Johns Hopkins University in Baltimore, Md., will analyze these data in the months following Astro-2, testing theories about whether the halo actually exists, and if so, how hot the gas is and how far it extends.

Mission Specialist Wendy Lawrence maneuvered the orbiter into position, Payload Commander Tammy Jernigan aligned the IPS and Payload Specialist Sam Durrance pointed HUT to again record ultraviolet spectrographic data of the "young" supernova remnant, SN 1006. This supernova remnant, first documented by Chinese astronomers in the year 1006, is giving HUT Guest Investigator Dr. John Raymond an opportunity to study the physics of shock waves before they hit a substantial amount of interstellar material (where the gas begins to cool off and slow down). Traveling at approximately 1,200 miles (2,000 kilometers) per second, the shock waves from this young supernova remnant are providing new insights into the characteristics of interstellar medium surrounding the site of a supernova explosion.

Parise also pointed HUT at elliptical galaxies called M60 and M89 last night. These galaxies are part of the Virgo cluster, a huge cluster of galaxies centered some 50 million light years from Earth. Astronomers have long been interested in these galaxies because of their very high ultraviolet upturn an excessive output of ultraviolet light for an old star population. HUT and UIT scientists are interested in these targets to learn more about what is causing the excessive amount of ultraviolet light. The theory was that younger star- formation galaxies produce more ultraviolet emissions than older star populations. However, observations of galaxies such as M60 and M89 are leading scientists to believe that some of these old low mass star populations may be in a more advanced stage of evolution. UIT is making a two- dimensional map of the ultraviolet upturn across the face of the M60 galaxy. Near the end of the M89 observation, WUPPE's dedicated experiment computer experienced a brief software problem. Durrance recycled power to the computer, which reset the software. The WUPPE science team has reactivated their telescope from the ground and resumed operations.

Durrance and Parise pointed HUT at several other celestial objects during the night. HUT observed planetary nebula NGC 1360, a cloud of gas and matter surrounding a star. The nebula glows because the ultraviolet radiation from the star ionizes the material in the surrounding cloud, which, in turn, emits energy at a variety of wavelengths. HUT scientists will study the ultraviolet light from the nebula and the star to learn more about the material making up the nebula and the star at its core.

UIT imaged NGC 752, an open star cluster, searching for hot accreting binaries, planetary nebulae and X-ray sources. UIT scientists are particularly interested in probing star clusters such as this for white dwarfs and other faint, hot stars.