+ Visit NASA.gov + Contact NASA   + Home Collection > NASA  Author > Benevenuti, P.  Author > Blaha, C.  Author > Dodorico, S.  Author > Gull, T. R.  Author > Humphreys, R. M.  NASA Center > NASA (non Center Specific)  Publication Year > 1981-1990 > 1983  Subject > A-C > Astronomy  Availability Options > Order From CASI > CD-ROM, DVD, Print  Item/Media Type > NASA Report > Technical Memorandum (TM)  Item/Media Type > Technical Report  Note: Start a new navigation search by selecting a link above     Previous Record | Next Record + Back to Results   + Printer Friendly Title: Ultraviolet spectroscopy of the brightest supergiants in M31 and M33 Author(s): Humphreys, R. M.; Blaha, C.; Dodorico, S.; Gull, T. R.; Benevenuti, P. Abstract: Ultraviolet spectroscopy from the IUE, in combination with groundbased visual and infrared photometry, are to determine the energy distributions of the luminous blue variables, the Hubble-Sandage variables, in M31 and M33. The observed energy distributions, especially in the ultraviolet, show that these stars are suffering interstellar reddening. When corrected for interstellar extinction, the integrated energy distributions yield the total luminosities and black body temperatures of the stars. The resulting bolometric magnitudes and temperatures confirm that these peculiar stars are indeed very luminous, hot stars. They occupy the same regions of the sub B01 vs. log T sub e diagram as do eta Car, P Cyg and S Dor in our galaxy and the LMC. Many of the Hubble-Sandage variables have excess infrared radiation which is attributed to free-free emission from their extended atmospheres. Rough mass loss estimates from the infrared excess yield rates of 0.00001 M sub annual/yr. The ultraviolet spectra of the H-S variables are also compared with similar spectra of eta Car, P Cyg and S For. NASA Center: NASA (non Center Specific) Publication Date: Mar 31, 1983 Document Source: CASI No Digital Version Available: Go to Tips On Ordering Document ID: 19830012604 Accession ID: 83N20875 Publication Information: Number of Pages = 44 Report Number: NAS 1.15:85258; NASA-TM-85258 Price Code: A03 Keywords: ANDROMEDA GALAXY; BLACK BODY RADIATION; SPECTRAL ENERGY DISTRIBUTION; STELLAR LUMINOSITY; VARIABLE STARS; BOLOMETERS; INFRARED SPECTROPHOTOMETERS; IUE; STELLAR EVOLUTION; ULTRAVIOLET SPECTROSCOPY; Accessibility: Unclassified; No Copyright; Unlimited; Publicly available; Final Technical Report Updated/Added to NTRS: 2004-11-03 + Back to Top + Sponsored by the NASA Scientific and Technical    Information Program + 2004 Vision for Space Exploration + Freedom of Information Act + NASA Web Privacy Policy and Important Notices + NASA Disclaimers, Copyright Notice,    and Terms and Conditions of Use NASA Official: Calvin Mackey Page Curator: NASA Center for AeroSpace Information (help@sti.nasa.gov) Last Updated: July 5, 2007