Astronomy Picture of the Day |
APOD: 2009 February 14 - IC 1805: The Heart Nebula
Explanation:
Sprawling across almost 200 light-years,
emission
nebula IC 1805
is a mix of glowing interstellar gas and dark dust clouds.
Derived from its
Valentine's-Day-approved shape,
its nickname is the Heart Nebula.
About 7,500 light-years away in the
Perseus spiral arm of
our galaxy, stars were born in IC 1805.
In fact, near the
cosmic heart's center are the
massive hot stars of a newborn star cluster
also known as Melotte 15, about 1.5 million years young.
A little ironically, the Heart Nebula is located in the
constellation
Cassiopeia.
From Greek mythology, the northern constellation
is
named for a vain and boastful queen.
This deep view
of the region around the Heart Nebula, cropped
from a larger mosaic, spans about
2.5 degrees on
the sky or about 5 times the diameter of the Full Moon.
APOD: 2009 February 12 - Zodiacal Light Vs. Milky Way
Explanation:
Two fundamental planes of planet Earth's sky compete
for attention in this remarkable wide-angle vista,
recorded on January 23rd.
Arcing above the horizon and into the night at the left
is a beautiful band of
Zodiacal Light - sunlight scattered by
dust
in the solar system's ecliptic plane.
Its opponent on the right is composed of the
faint stars, dust clouds, and nebulae along
the plane of our
Milky Way Galaxy.
Both celestial bands stand above the domes and towers of the
Teide Observatory
on the island of Tenerife.
Also out to play in the pristine, dark skies over the Canary Islands,
are brilliant Venus (lower left),
the distant
Andromeda Galaxy (near center),
and the lovely
Pleiades star cluster (top center).
Of course, seasoned skygazers might even spot
M33, the
California Nebula,
IC1805, and the
double star cluster of Perseus.
(Need some help? Just slide your cursor over the picture.)
APOD: 2009 January 30 - NGC 1579: Trifid of the North
Explanation:
Colorful NGC 1579
resembles the better known
Trifid Nebula, but lies much farther north in planet
Earth's sky, in the heroic constellation
Perseus.
About 2,100 light-years away and 3 light-years across,
NGC 1579 is, like the Trifid,
a study in contrasting blue and red colors, with dark dust lanes
prominent in the nebula's central regions.
In both, dust reflects starlight to produce
beautiful blue reflection nebulae.
But unlike the Trifid,
in NGC 1579
the reddish glow is
not emission from clouds of glowing hydrogen
gas excited by ultraviolet light from a nearby hot star.
Instead, the dust in NGC 1579 drastically diminishes, reddens, and
scatters the light from an embedded,
extremely young,
massive star, itself a strong emitter of the characteristic red
hydrogen alpha light.
APOD: 2009 January 3 - Double Cluster in Perseus
Explanation:
Some 7,000 light-years away, this pair of open or galactic
star clusters is an easy
binocular target,
a lovely starfield in the
northern constellation
Perseus.
Also visible to
the unaided eye from dark sky areas,
it was cataloged in 130 BC by Greek astronomer
Hipparchus.
Now known as
h and
chi Persei, or
NGC 869(above right) and NGC 884, the clusters
themselves are separated by only a few hundred light-years and
contain stars much younger and hotter than the Sun.
In addition to being physically close together, the clusters' ages
based on
their individual stars are similar - evidence that
both clusters were likely a product of the same
star-forming region.
APOD: 2008 November 21 - M76 Above and Below
Explanation:
Also known by the popular name the "Little Dumbbell Nebula",
M76 is
one of the fainter objects listed in Charles Messier's 18th century
Catalog of
Nebulae and Star Clusters.
Like its better-known namesake M27
(the Dumbbell Nebula), M76 is recognized
as a planetary
nebula - a gaseous shroud cast off by a
dying sunlike star.
The nebula itself is thought to be shaped more like a donut, its
central box-like appearance
due to our nearly edge-on view.
Gas expanding more rapidly away from the donut hole produces the
more extensive, far flung material in
this remarkable image
that uses narrow-band
filters to highlight the
emission from hydrogen (in red) and
oxygen atoms (in greenish blue).
In particular, complex oxygen emission features are seen
above and below the main nebula to a degree not detected
in most images of M76.
Distance estimates place M76 about 3 to 5 thousand light-years away
toward the heroic constellation
Perseus,
making the nebula over a
light-year in diameter.
APOD: 2008 October 24 - Amazing Comet Holmes
Explanation:
One year ago,
Comet 17P/Holmes amazed sky watchers across planet Earth.
A stunningly rapid
outburst
transformed it from a faint comet quietly
orbiting the Sun
with a period of about 7 years to
a naked-eye comet rivaling the brighter stars in the constellation
Perseus.
Its largely tail-less shape, as in
this wide-angle
view recorded on November 11, 2007, became well-known to
astronomers trying to
unravel the mystery of the comet's
surprising outburst .
Still,
Comet Holmes had a dim ion tail that
was seen to separate from the bright
coma.
In this image, the separated tail creates the illusion
of a reflection nebula.
It appears as a faint bluish haze right of center against a
background of stars in the loosely grouped
Alpha
Persei Moving Cluster.
APOD: 2008 September 26 - Moon Rays over Byurakan Observatory
Explanation:
On September 7th, the first quarter Moon and passing clouds
contributed to a dramatic night sky over the
Byurakan
Astrophysical Observatory.
This panoramic view begins at the left looking toward the
eastern horizon and the rising stars of the constellation
Perseus.
Sweeping your gaze to the right (south), you'll find the
large observatory dome, housing a 2.6 meter diameter telescope,
backlit by lights from nearby Yerevan,
capital city of Armenia.
Fittingly poised above the observatory dome is the bright, giant
star Enif
in the high-flying constellation
Pegasus.
Farther to the right, the brightest celestial beacon
just above the clouds is our Solar System's ruling
gas giant Jupiter.
At the far right, the Moon is nearly hidden by an approaching
cloudbank, but the clouds themselves actually cast shadows
in the bright moonlight, creating
the effect of Moon rays
across the evening sky.
APOD: 2008 September 11 - Mountain Top Meteors
Explanation:
A mountain top above the clouds
and light-polluted cities
was a good place
to go to watch this August's
Perseid
meteor shower.
In fact, this composite picture from one of the highest points
in Romania, the Omu summit (2,507 meters) in the
Southern
Carpathian Mountains, captures about 20 of the shower's
bright streaks against a
starry night sky.
The cosmic debris stream that creates the shower is composed of
dust particles moving along parallel paths, following the orbit
of their parent comet
Swift-Tuttle.
Looking toward the shower's
radiant point
in the constellation Perseus,
perspective causes the parallel meteor streaks to appear
to diverge.
But looking directly away from the radiant point, as in this view,
perspective actually makes the Perseid meteors seem to be converging
toward a point below the horizon.
APOD: 2008 August 22 - Active Galaxy NGC 1275
Explanation:
Active galaxy NGC 1275
is the central, dominant member of the large and
relatively nearby
Perseus Cluster of Galaxies.
A prodigious source of
x-rays
and
radio
emission, NGC 1275 accretes
matter as entire galaxies fall into it, ultimately
feeding a supermassive black hole at the galaxy's core.
This stunning
visible
light image from the Hubble Space Telescope
shows galactic debris
and filaments of glowing gas,
some up to 20,000 light-years long.
The filaments persist in NGC 1275, even though
the turmoil of galactic collisions should destroy them.
What keeps the filaments together?
Recent work
indicates that the structures, pushed out
from the galaxy's center by the black hole's activity, are
held together by magnetic fields.
To
add x-ray data
from the Chandra Observatory and radio data from
the Very Large Array
to the Hubble image, just slide
your cursor over the picture.
In the resulting composite, x-rays highlight the
shells of hot gas
surrounding the center of the galaxy, with radio emission filling
giant bubble-shaped cavities.
Also known as Perseus A,
NGC 1275
spans over 100,000 light years and
lies about 230 million light years away.
APOD: 2008 August 14 - Perseid Trail
Explanation:
This bright and colorful
meteor flashed through Tuesday's
early morning skies, part of the annual
Perseid Meteor
Shower.
The lovely image is one of over 350 frames captured on August 12
from the Joshua Tree National Park,
in California, USA .
Dust from comet
Swift-Tuttle
is responsible for the
Perseids, creating the northern hemisphere's regular
summer sky show.
The comet dust is vaporized as it enters the atmosphere at upwards
of 60 kilometers per second, producing visible trails that begin at
altitudes of around 100 kilometers.
Of course, the trails point back to a
radiant point in
the constellation Perseus, giving the meteor shower its name.
Recorded after moonset, the starry background features the
bright star Vega on the right.
Extending below the western horizon is the faint band of the
northern Milky Way.
APOD: 2008 June 6 - Two-Armed Spiral Milky Way
Explanation:
Gazing out from within
the Milky Way, our own galaxy's true structure is difficult to discern.
But an
ambitious survey effort with the
Spitzer Space Telescope now
offers convincing evidence
that we live in a large galaxy distinguished by two main
spiral arms
(the Scutum-Centaurus and Perseus arms)
emerging from the ends of a large central bar.
In fact, from a vantage point that viewed our galaxy
face-on,
astronomers in distant galaxies
would likely see
the Milky Way
as a two-armed barred spiral
similar to this
artist's illustration.
Previous investigations have identified
a smaller central barred structure and four spiral arms.
Astronomers still
place the Sun about a third of the way in from
the Milky Way's outer edge, in a minor arm called
the Orion Spur.
To locate the Sun and identify the Milky Way's newly mapped features,
just place your cursor over the image.
APOD: 2008 May 20 - The Perseus Cluster of Galaxies
Explanation:
Here is one of the
largest objects that anyone will ever see on the sky.
Each of these fuzzy blobs is a galaxy, together making up the
Perseus Cluster, one of the closest
clusters
of galaxies.
The cluster is seen through a foreground of faint stars in our own
Milky Way Galaxy.
Near the cluster center, roughly 250 million light-years
away, is the cluster's dominant galaxy NGC 1275,
seen above as the large galaxy on the image left.
A prodigious source of
x-rays and radio emission,
NGC 1275 accretes
matter as gas and galaxies fall into it.
The Perseus Cluster of Galaxies
is part of the Pisces-Perseus supercluster
spanning over 15 degrees and containing over 1,000 galaxies.
At the distance of NGC 1275, this view covers about 7.5 million
light-years.
APOD: 2007 December 21 - Horizon to Horizon
Explanation:
Scroll right and journey from horizon to horizon as your gaze sweeps
through
the zenith in
the night
sky over Beg-Meil, France.
Recorded on December 13th,
the entertaining panorama
(image key)
covers 210 degrees
in 21 separate exposures, beginning on the beach with bright star
Sirius rising in the southeast.
Look up (pan right) to encounter the nebula rich constellation
of Orion and
continue on to find the lovely Pleiades
star cluster.
Farther along, higher in the sky, is the famous
Comet Holmes,
still
gracing the northern hemisphere's night with its
remarkable expanding coma.
Finally, just before diving into the
urban glow from city lights along
the northwestern horizon (far right), check out the
double star cluster in
Perseus and take in the cosmic streak of a bright
Geminid
Meteor.
APOD: 2007 December 7 - Double Cluster in Perseus
Explanation:
Skygazers recently following
Comet Holmes
have probably also chanced across this
lovely starfield,
not far from the comet on the sky in the constellation
Perseus.
Some 7,000 light-years away, this pair of open or galactic
star clusters is an easy
binocular target and is visible to the unaided eye from
dark sky areas.
In fact, it was cataloged in 130 BC
by Greek astronomer Hipparchus.
Now known as
h and
chi Persei, or
NGC 869(left) and NGC 884, the clusters
themselves are separated by only a few hundred light-years and
contain stars much younger and hotter than the Sun.
In addition to being physically close together, the clusters' ages
based on
their individual stars are similar - evidence that
both clusters were likely a product of the same star-forming
region.
APOD: 2007 December 5 - Comet Holmes Over Hungary
Explanation:
Comet Holmes refuses to fade.
The
unusual comet that surprisingly brightened nearly a
million-fold in late October continues to
remain visible
to the unaided eye from dark locations.
Night to night,
Comet 17P/Holmes
is slowly gliding through the
constellation Perseus,
remaining visible to northern observers during much of the night right from sunset.
Pictured above,
Comet Holmes was captured from
Hungary last week.
The remarkable snowball continues to retain a
huge coma, but now shows very little of a
tail.
To the far right is the
open cluster of stars
NGC 1245.
How much longer
Comet Holmes will remain visible
to the unaided eye is unknown.
APOD: 2007 November 29 - Stardust in Perseus
Explanation:
This cosmic expanse of dust, gas, and stars covers some 4 degrees
on the sky in the heroic constellation
Perseus.
Centered in the
gorgeous skyscape
is the dusty blue reflection nebula
NGC 1333,
about 1,000 light-years away.
At that estimated distance, the field
of view is nearly 70 light-years across.
Other reflection nebulae are scattered around,
along with remarkable
dark dust nebulae and
the faint reddish glow of hydrogen gas.
These dust and gas clouds lie near the edge of a large
molecular
cloud.
Themselves telltale signs of star-forming regions, they
tend to hide
the newly formed stars and young stellar objects or protostars from
prying optical telescopes.
Collapsing due to
self-gravity, the
protostars
form around dense cores embedded in the molecular cloud.
APOD: 2007 November 28 - Comet Holmes from the Hubble Space Telescope
Explanation:
Why did Comet Holmes brighten?
The unexpectedly bright
Comet 17P/Holmes
continues to grace northern skies as a
naked-eye
addition to the constellation Perseus.
Any northern
sky enthusiast with a
dark sky, a
bright curiosity, and a
recent sky map
should still be able to
locate the comet in a few minutes.
What is seen, however, is primarily the sun-light reflecting dust
coma.
It surrounds an iceberg nucleus
too small and too faint to discern.
Clues to the nearly
million-fold brightness increase
are therefore being sought in dramatic images of the
enigmatic comet's central
regions taken earlier this month by the
Hubble Space
Telescope.
One such Hubble image,
shown above, indicates a still unresolved dense
central dust cloud near the
nucleus,
surrounded by a more complex, anisotropic coma.
The Hubble images do not show any
obvious fragmentation
of the nucleus, however, as was seen last year in
Comet Schwassman-Wachmann 3.
Observers around and above the world will continue to study this
unusual addition to the night sky.
APOD: 2007 November 21 - Expansive Comet Holmes
Explanation:
The spherical coma of Comet Holmes has swollen
to a diameter of over 1.4 million kilometers, making the
tenuous, dusty cloud even
bigger
than the Sun.
Scattering sunlight, all that dust and gas came from the comet's
remarkably
active nucleus, whose diameter before
the late October
outburst was estimated to be a
mere 3.4 kilometers.
In this sharp image, recorded on November 14 with
the Canada-France-Hawaii Telescope,
stars are easily visible right through the outer
coma,
while the
nucleus is buried inside the condensed,
bright region.
The bright region of the coma seems offset from
the center, consistent with the idea that a
large fragment drifted away from the nucleus
and disintegrated, producing the comet's spectacular outburst.
Of course, more
recent
images of Holmes also
show the bright star Mirfak (Alpha Persei) shining through
as the comet sweeps slowly through the constellation
Perseus.
APOD: 2007 November 17 - Forest and Sky
Explanation:
With pine trees in dim silhouette,
this
skyscape
from Breil-sur-Roya in southern France was
captured on November 11.
In the early evening scene, a satellite seems to streak through the
branches, while bright, round, fuzzy
Comet
Holmes appears to lie
just beyond them, near the stars of the constellation
Perseus.
Mirfak,
alpha star of Perseus, is the brightest
star above the comet and to the right.
Next Monday (November 19), Holmes will be close enough to
Mirfak to view the star through the remarkable comet's expanding
coma.
Recent
measurements place the dusty coma's diameter at about
1.4 million kilometers, even larger
than the
Sun.
APOD: 2007 November 13 - The Inner Coma of Comet Holmes
Explanation:
What's happening to Comet Holmes?
The rare comet
remains visible to the unaided eyes of northern observers as
an unusual small puff ball in the constellation of
Perseus.
A high resolution set of images of the comet's inner
coma,
taken last week and shown above, reveals significant detail.
Close inspection shows numerous faint streamers that are possibly the result of
jets emanating from the comet's nucleus.
Comet Holmes has remained
surprisingly bright over the past week, with
luminosity
estimates ranging from between visual
magnitudes 2 to 3,
making it brighter than most stars visible on a dark sky.
The above image
of Comet Holmes
was made with a
small automated 0.38-meter telescope hirable over the web for a small fee.
APOD: 2007 November 9 - Skyscape with Comet Holmes
Explanation:
This gorgeous skyscape spans some 10 degrees across the
heroic constellation
Perseus, about the size of a generous binocular
field of view.
The deep exposure includes bright stars,
emission nebulae,
star clusters, and, of course, the
famous Comet Holmes.
To identify the celestial landmarks,
just place your cursor over the image.
The brightest star in view, Alpha Persei, is itself
surrounded by a loose cluster of stars - the
Alpha Per
Moving Cluster -
at a distance of about 600 light-years.
But, at a distance of a mere 14
light-minutes bright
Comet
Holmes still dominates the scene with its
fluorescing greenish coma
and foreshortened blue tail.
APOD: 2007 November 3 - Golden Comet Holmes
Explanation:
Surprising Comet Holmes remains easily visible
as a round, fuzzy cloud in the northern constellation
Perseus.
Skywatchers with telescopes, binoculars, or those that
just decide to look up
can
enjoy the solar system's latest
prodigy as it glides
about 150 million kilometers from Earth, beyond the orbit of Mars.
Still expanding,
Holmes now appears to be about 1/3 the
size of the Full Moon, and many observers report a
yellowish tint to the dusty
coma.
A golden color does dominate this
telescopic view recorded on November 1,
showing variations across the coma's bright central region.
But where's the comet's tail?
Like any good
comet, Holmes'
tail would tend to point away from the Sun.
That direction is nearly along our line-of-sight behind the comet,
making its tail very difficult to see.
APOD: 2007 October 26 - Comet Holmes in Outburst
Explanation:
Comet 17P/Holmes
stunned comet watchers
across planet Earth earlier this week.
On October 24, it increased in brightness over half a million
times in a matter of hours.
The outburst transformed it from an obscure and faint
comet quietly orbiting the Sun with a period of about 7
years to a naked-eye comet
rivaling the brighter stars in the
constellation Perseus.
Recorded on that date,
this view
from Tehran, Iran highlights
the comet's (enhanced and circled)
dramatic new visibility in urban skies.
The inset (left) is
a telescopic image
from a backyard in Buffalo, New York showing the
comet's greatly expanded
coma,
but apparent lack of a tail.
Holmes' outburst
could be due to a sudden exposure of
fresh cometary ice or even the breakup of the
comet nucleus.
The comet may well remain bright in the coming days.
APOD: 2007 August 16 - Moonless Perseid Sky
Explanation:
Last weekend, dark, moonless night skies brought many sightings of
Perseid meteors to
skygazers
all over planet Earth.
Early Sunday morning astronomer John Chumack's camera captured
this Perseid
meteor streak with a flare near the end of its
track over Yellow Springs, Ohio.
The single, four minute long exposure looks toward the constellation of
Taurus and the eastern horizon.
The meteor streak points back to the
annual meteor
shower's radiant in
Perseus off the upper left corner of the picture.
Of course, the view includes the well-known
Pleiades
Star cluster (near top center) with a
bright yellowish planet Mars below it.
Also seen with a yellowish tint but not quite as bright as Mars,
the giant star
Aldebaran
anchors the V-shaped
Hyades
star cluster left of center, above the trees.
APOD: 2007 August 15 - Mysterious Streaks Over Turkey
Explanation:
What are they?
Five streaks near the bottom of the above image taken near
Ankara,
Turkey
on Sunday would be identified at first glance as meteors from the
Perseids meteor shower peaking just that night.
Unexpectedly, however, these streaks do not point back to the Perseids
radiant in
Perseus.
Their origin is therefore somewhat unclear.
The above image was captured over the time span of 40 minutes.
Other visible celestial icons include the constellation
Orion and the
Pleiades star cluster.
One hypothesis is that the
streaks are part of a microburst from a
much less active meteor shower known as the
Alpha Ursae Majorids.
Another possibility is that they are parts of a
satellite
that broke up as it
re-entered the Earth's atmosphere.
A discussion of these possibilities can be found
here.
This year's
Perseids meteor shower
was a good one, as it was particularly active and
corresponded with the dark skies that come with a
new moon.
APOD: 2007 August 12 - Raining Perseids
Explanation:
Tonight is a good night to see meteors.
Comet dust will rain down on planet Earth, streaking
through dark skies in the annual
Perseid meteor shower.
While enjoying the
anticipated space weather, astronomer
Fred Bruenjes recorded a series of many 30 second long exposures
spanning about six hours on the night of 2004 August 11/12 using a
wide angle lens.
Combining those frames which captured
meteor flashes, he produced
this dramatic view of the
Perseids of summer.
Although the comet dust particles are traveling parallel
to each other, the resulting shower meteors clearly seem to
radiate from a single point on the sky in the
eponymous
constellation Perseus.
The radiant effect is due to
perspective, as the parallel
tracks appear to converge at a distance.
Bruenjes notes that there are 51 Perseid meteors in
the composite image,
including one seen nearly head-on.
This year, the Perseids Meteor Shower is expected to peak
after midnight tonight, in the moonless early morning hours of August 12.
APOD: 2007 May 21 - In the Center of Reflection Nebula NGC 1333
Explanation:
The dust is so thick in the center of NGC 1333 that you can hardly see the stars forming.
Conversely, the very
dust clouds that hide the stars also reflects their
optical light,
giving NGC 1333's predominantly blue glow the general designation of a
reflection nebula.
A highly detailed image of the nebula,
shown above,
was taken recently by the
Mayall 4-meter telescope
on Kitt Peak in
Arizona,
USA
and released to honor astronomer
Stephen Strom
on his retirement.
Visible near the image top are vast
blue regions of dust
predominantly reflecting the light from
bright massive stars.
Visible in the thick central dust are not only newly formed stars but
red jets and red-glowing gas energized by the light and
winds from recently formed young stars.
The NGC 1333
nebula contains hundreds
of newly formed stars that are less than one million years old.
Reflection nebula
NGC 1333 lies about 1,000
light years away toward the
constellation of Perseus.
APOD: 2007 March 31 - Hale-Bopp: The Great Comet of 1997
Explanation:
Ten short years ago,
Comet
Hale-Bopp rounded
the Sun and offered a dazzling spectacle in planet Earth's
night.
This
stunning view, recorded shortly after the comet's
perihelion passage on April 1, 1997, features the memorable
tails
of Hale-Bopp -- a whitish dust tail and blue ion tail.
Here, the ion tail extends well over ten degrees across
the northern sky, fading near the double
star clusters
in Perseus, while the head of the comet lies near
Almach,
a bright star in the constellation Andromeda.
Do you remember Hale-Bopp?
The photographer's sons do, pictured in the foreground at
ages 12 and 15.
In all, Hale-Bopp was reported as visible
to the naked eye from roughly late May 1996 through September 1997.
APOD: 2006 October 6 - Dusty NGC 1333
Explanation:
Dusty NGC 1333
is seen in visible light as a
reflection nebula,
dominated by bluish hues characteristic
of starlight reflected by dust.
But at longer infrared wavelengths, the
interstellar
dust itself glows.
Moving your cursor over the picture will match up a
visible
light view with a false-color infrared image of the region from the
Spitzer Space Telescope.
The penetrating
infrared view unmasks youthful stars
that are otherwise obscured by the
dusty clouds
that formed them.
Also revealed are greenish streaks and splotches that seem to
litter the region.
The structures trace the glow of
cosmic jets blasting away
from emerging young stellar objects and plowing into the
cold cloud material.
In all, the chaotic
environment likely resembles one in which our own
Sun formed over 4.5 billion years ago.
NGC
1333 is a mere 1,000 light-years distant in the constellation
Perseus.
APOD: 2006 August 17 - Comet Dust over Colorado
Explanation:
The rock formation in the foreground of this night view
was recorded on August 10,
illuminated by light from a waning gibbous Moon.
Even though the sky above also
scatters the bright moonlight, a brilliant meteor was captured as it flashed
across
the scene during the 30 second long exposure.
Of course, the meteor was part of the
annual rain of dust from
periodic Comet Swift-Tuttle known as the
Perseid Meteor Shower.
Leaving trails that point back to a
radiant in the
constellation Perseus, the
ancient dust particles are
vaporized as they enter the atmosphere at about 60 kilometers
per second, their visible streaks beginning at altitudes
of around 100 kilometers.
And though it looks like the knuckles of a giant hand,
the curious rock formation can be
found in Colorado National Monument park, USA,
planet Earth.
APOD: 2006 July 20 - Constellation Construction
Explanation:
This lovely
twilight scene, recorded last April,
finds a young crescent Moon
low in the west at sunset.
Above it, stars shine in the darkening sky
but they too are soon to drop below the western horizon.
These stars and constellations are prominent in the northern
hemisphere winter sky and as
the season changes, slowly give way to the
stars of summer.
Sliding your mouse over the picture will detail the
constellations and stars in view,
including Orion, Gemini, Auriga, Perseus,
and the Hyades and Pleiades star clusters.
APOD: 2006 May 25 - NGC 1579: Trifid of the North
Explanation:
Colorful NGC 1579
resembles the better known
Trifid Nebula, but lies much farther north in planet
Earth's sky, in the heroic constellation
Perseus.
About 2,100 light-years away and 3 light-years across,
NGC 1579 is a captivating study in color.
Like the Trifid,
NGC 1579 is a dusty star forming region
providing contrasting emission and reflection
nebulae in the
same field - the characteristic red glow of hydrogen gas
and the blue of reflected starlight.
Also like the Trifid, dark dust
lanes are prominent in the nebula's central regions.
In fact, obscuring dust is pervasive in
NGC 1579,
drastically dimming the visible light from the
massive, young, hot stars still
embedded
in the cosmic cloud.
APOD: 2006 April 13 - Star Cluster Dreams
Explanation:
Located some 7,000 light-years away toward the constellation
Perseus, this pair of open
or galactic star clusters really
is visible to the unaided eye and was cataloged in 130 BC
by Greek astronomer Hipparchus.
Now known as
h and
chi Persei (NGC 869/884), the clusters
themselves are separated by a few hundred light-years and
contain stars much younger, and hotter than the Sun.
But what if this famous double star cluster were closer,
say only 700 light-years distant from our fair solar system,
crowding our sky with stars?
Astrophotographer Jose Suro also imagines a
clear, moonless,
dark night sky on a warm evening near tranquil waters.
The foreground is illuminated by starlight in
his composited
dreamlike image of the cluster pair.
He notes that while the solar system is not in the
vicinity of such rich clusters of stars,
dark night skies
and warm evenings
can
still be inspiring
on planet Earth.
APOD: 2005 December 30 - The Perseus Cluster of Galaxies
Explanation:
Here is one of the
largest objects that anyone will
ever see on the sky.
Each of these fuzzy blobs is a galaxy, together making up the
Perseus Cluster, one of the closest
clusters
of galaxies.
The cluster is seen through a foreground of faint stars in our own
Milky Way Galaxy.
Near the cluster center, roughly 250 million light-years
away, is the cluster's dominant galaxy NGC 1275,
seen
here just left of picture center.
A prodigious source of
x-rays and radio emission,
NGC 1275 accretes
matter as gas and galaxies fall into it.
The Perseus Cluster of Galaxies
is part of the
Pisces-Perseus supercluster
spanning over 15 degrees and containing over 1,000 galaxies.
At the distance of NGC 1275, this view covers about 1.5 million
light-years.
APOD: 2005 December 8 - X-Rays from the Perseus Cluster Core
Explanation:
The Perseus Cluster of thousands of galaxies,
250 million light-years distant, is
one of
the most massive objects
in
the Universe and the brightest galaxy cluster in the
x-ray sky.
At its core lies the giant
cannibal galaxy Perseus A
(NGC
1275), accreting matter as
gas and galaxies fall into it.
This deep
Chandra Observatory x-ray image spans about 300,000 light-years
across the galaxy cluster core.
It shows
remarkable details
of x-ray emission from the monster galaxy and
surrounding hot (30-70 million degrees C) cluster gas.
The bright central source is the supermassive
black
hole at the core of Perseus A itself.
Low density regions are seen as dark bubbles or voids,
believed to be generated by cyclic outbursts of activity
from the central black hole.
The activity creates pressure waves -
sound waves on a cosmic scale-
that ripple through the x-ray hot gas.
Dramatically, the blue-green wisps just above centre in the
false-color view are likely x-ray shadows of
the remains of a small galaxy falling into the burgeoning
Perseus A.
APOD: 2005 November 24 - Dusty NGC 1333
Explanation:
Dusty NGC 1333
is seen as a reflection nebula
in visible light images, sporting bluish hues characteristic
of starlight reflected by dust.
But at longer infrared wavelengths, the
interstellar
dust itself glows - shown in red in this false-color
Spitzer Space Telescope image.
The penetrating
infrared view also shows youthful stars
that would otherwise still be obscured by the
dusty clouds
which formed them.
Notably, greenish streaks and splotches that seem to
litter the region trace the glow of
cosmic jets blasting away
from emerging young stellar objects as the jets plow into the
cold cloud material.
In all, the chaotic
scene likely resembles one in which our own
Sun formed over 4.5 billion years ago.
NGC
1333 is a mere 1,000 light-years distant in the constellation
Perseus.
APOD: 2005 October 11 - NGC 869 and NGC 884: A Double Open Cluster
Explanation:
Most star clusters are singularly impressive.
Open clusters NGC 869 and NGC 884,
however, are doubly impressive.
Also known as "h and chi Persei", this unusual
double cluster, shown above, is bright enough to be seen from a
dark location without even
binoculars.
Although their discovery surely predates
written history, the Greek astronomer
Hipparchus notably cataloged the "double
cluster".
The clusters are over 7,000 light years distant toward the
constellation of
Perseus, but are separated by only hundreds of light years.
APOD: 2005 August 15 - Perseid Meteors and the Milky Way
Explanation:
Where will the next Perseid meteor appear?
Sky enthusiasts who trekked outside for the
Perseid meteor shower that peaked over the past few days
typically had this question on their mind.
The above movie, where the time-line has been digitally altered, captures part of that very mystery.
Eight meteors from the night of August 12 and
the morning of
August 13 have been identified in the movie so far, seven of which are
Perseids.
Can you identify the non-Perseid meteor?
Since all Perseid meteors appear to come from the
constellation of Perseus, the non-Perseid meteor is the one that streaks
in a different direction.
Early reports are that
this year's Perseids were unfortunately a bit disappointing.
The above digital mosaic was taken from
Alsace,
France, with the photogenic
band of our
Milky Way Galaxy far in the background.
APOD: 2005 August 12 - A Meteor Shower Fireball Movie
Explanation:
Go outside tonight and see a celestial light show --
the later the better.
Tonight is the peak of the month-long
Perseid Meteor Shower.
Although visible every year at this time, the
Perseids are expected to appear particularly active
this year due to the relative absence of glare from the Moon during the peak.
Tonight, a thin moon will set a
few hours after the Sun, leaving a moonless and dark sky.
All through the night, all over the sky,
meteors will appear to shoot out the constellation Perseus and across the sky.
The rate of meteors and
fireballs is not known for sure,
but expected by some to be as high as
one meteor flash every minute.
Lucky sky gazers
might be treated to a bright fireball like the one pictured above.
That fireball was
captured by a digital recorded over
Wise Observatory
during the 2001 Leonid Meteor Shower.
The meteor shower
poses no danger as few, if any, of the
sand-sized flaring bits are expected to reach the ground.
APOD: 2005 August 6 - Raining Perseids
Explanation:
Comet dust rained down on planet Earth last August, streaking
through dark skies in the annual
Perseid meteor shower.
So, while enjoying the
anticipated space weather, astronomer
Fred Bruenjes recorded a series of many 30 second long exposures
spanning about six hours on the night of August 11/12 using a
wide angle lens.
Combining those frames which captured
meteor flashes, he produced
this dramatic view of the
Perseids of summer.
Although the comet dust particles are traveling parallel
to each other, the resulting shower meteors clearly seem to
radiate from a single point on the sky in the
eponymous
constellation Perseus.
The radiant effect is due to
perspective, as the parallel
tracks appear to converge at a distance.
Bruenjes notes that there are 51 Perseid meteors in
the composite image,
including one seen nearly head-on.
This year, the Perseids
Meteor Shower will peak in the
early morning hours on Friday, August 12.
APOD: 2005 July 25 - Unusual Gas Filaments Surround Galaxy NGC 1275
Explanation:
How were the unusual gas filaments surrounding galaxy NGC 1275 created?
No one is sure. Galaxy NGC 1275 is the
central dominant galaxy of the
Perseus Cluster of Galaxies,
a cluster with many member galaxies visible in the above image.
In visible light, NGC 1275 appears to show a
spectacular collision between two distinct galaxies.
The galaxy and cluster are also bright emitters of
X-rays.
The unusual gas filaments are shown above in a very
specific color of light emitted by
hydrogen, here artificially colored pink.
Possible origins for the filaments may involve details of the collision between the two galaxies, or alternatively, interactions between a
galactic center black hole and the surrounding
intracluster gas.
NGC 1275,
pictured above, spans about 100,000
light years and lies about 230 million light years distant toward the
constellation of Perseus.
APOD: 2005 January 5 - Comet Machholz in View
Explanation:
Good views of
Comet Machholz
are in store for northern
hemisphere comet watchers in January.
Now making its closest approach to planet Earth,
the comet will pass near the lovely
Pleiades star cluster on
January 7th
and the double star cluster in
Perseus on January 27th
as Machholz moves relatively quickly
through the evening sky.
Currently just visible to the unaided eye from
dark locations,
the comet should be an easy target in binoculars or a small
telescope.
In fact, this telephoto time exposure from January 1
shows Comet Machholz
sporting two lovely tails in skies over Colorado, USA.
Extending to the left,
strands
of the comet's ion or gas tail are
readily affected by the solar breeze and point
away from the Sun.
Dust, which tends to trail along the
comet's orbit,
forms the tail jutting down and to the right.
APOD: 2004 October 25 - The Perseus Cluster of Galaxies
Explanation:
Here is one of the largest objects that anyone will ever see on the sky.
Each of the fuzzy blobs in the
above picture is a galaxy, together making up the
Perseus Cluster, one of the closest
clusters of galaxies.
The cluster is seen through the foreground of faint stars in our own
Milky Way Galaxy.
It takes light roughly 300 million years to get here
from this region of the Universe, so we see this
cluster as it existed before the age of the
dinosaurs.
Also known as Abell 426, the center of the
Perseus Cluster is a prodigious source of
X-ray radiation, and so helps astronomers explore
how clusters formed and how gas and
dark matter interact.
The Perseus Cluster of Galaxies is part of the
Pisces-Perseus supercluster of galaxies, which spans over
15 degrees and contains over 1000 galaxies.
APOD: 2004 August 20 - Raining Perseids
Explanation:
Comet dust rained down on planet Earth last week, streaking
through dark skies in the annual
Perseid meteor shower.
So, while enjoying the
anticipated space weather, astronomer
Fred Bruenjes recorded a series of many 30 second long exposures
spanning about six hours on the night of August 11/12 using a
wide angle lens.
Combining those frames which captured
meteor flashes, he produced
this dramatic view of the
Perseids of summer.
Although the comet dust particles are traveling parallel
to each other, the resulting shower meteors clearly seem to
radiate from a single point on the sky in the
eponymous
constellation Perseus.
The radiant effect is due to
perspective, as the parallel
tracks appear to converge at a distance.
Bruenjes notes that there are 51 Perseid meteors in
the composite image,
including one seen nearly head-on.
APOD: 2004 August 13 - Perseid Fireball Over Japan
Explanation:
Enjoying the bright Moon's absence
from early morning skies, observers around the world
reported lovely displays during this year's
Perseid meteor shower.
As anticipated, peak rates were about one meteor per minute.
Though most Perseids were faint, this bright and colorful
fireball meteor flashed through
skies over Japan
on August 12 at 0317 JST.
Ending at the upper right, the
meteor's trail points
down and to the left, back to the shower's
radiant
point between the constellations
of Perseus and Cassiopeia,
seen here
just above the tower structure in the foreground.
The Pleiades star cluster is also visible well below
the meteor's trail.
Perseid
shower meteors can be traced to
particles of dust
from the tail of comet Swift-Tuttle.
The comet dust impacts the atmosphere
at speeds of around 60 kilometers per second.
While this annual shower's peak has come and gone,
Perseid
meteors should still be visible over the next few nights, but at
a greatly reduced rate.
APOD: 2004 August 11 - A Perseid Meteor
Explanation:
The ongoing
Perseid Meteor Shower should be at its strongest
tonight and tomorrow night.
Although meteors should be visible all night long,
the best time to watch will be between 2:00 AM and
dawn each night.
In dark, moonless, predawn
skies you may see dozens of meteors per hour.
Sky enthusiasts in Europe and
Asia might see an unusual burst of meteors near 2100 hours
UT.
Grains of cosmic sand and gravel shed from
Comet Swift-Tuttle will
streak across the sky as they vaporize during entry into Earth's atmosphere.
Tracing the meteor trails backwards,
experienced skygazers will find they converge
on the constellation Perseus, thus this
annual meteor shower's name.
Pictured
above is a Perseid meteor from 2002 over a rock formation in
the US Southwest desert.
Shadowing and blurring are caused by the long 10-minute exposure.
The brightest Perseids can be seen from anywhere on Earth
by monitoring the continuously returning images from the
Night Sky Live
cameras.
APOD: 2003 December 2 - NGC 869 and NGC 884: A Double Open Cluster
Explanation:
Most star clusters are singularly impressive.
Open clusters NGC 869 and NGC 884,
however, are doubly impressive.
Also known as "h and chi Persei", this unusual
double cluster, shown above, is bright enough to be seen from a
dark location without even binoculars.
Although their discovery surely predates
written history, the Greek astronomer
Hipparchus notably cataloged the "double
cluster".
The clusters are over 7000 light years distant toward the
constellation of
Perseus, but are separated by only hundreds of light years.
APOD: 2003 September 12 - A Note on the Perseus Cluster
Explanation:
A truly enormous collection of thousands of galaxies, the
Perseus Cluster - like other
large galaxy clusters - is
filled with hot, x-ray emitting gas.
The x-ray hot gas
(not the individual galaxies) appears
in the left panel above, a false color
image
from the Chandra Observatory.
The bright central source flanked by two
dark cavities is
the cluster's supermassive black hole.
At right, the panel shows the
x-ray image
data specially processed
to enhance contrasts and reveals a strikingly regular
pattern of pressure waves
rippling through
the hot gas.
In other words,
sound
waves, likely generated by bursts of
activity from the black hole, are ringing through the
Perseus Galaxy Cluster.
Astronomers infer that these previously unknown sound waves are a
source of energy which keeps the cluster gas so hot.
So what note is the Perseus Cluster playing?
Estimates of the distance between the wave peaks and sound speed
in the cluster gas suggests
the cosmic note is about 57 octaves below B-flat above middle C.
APOD: 2003 August 9 - A Perseid Aurora
Explanation:
Just after the
Moon set but before the
Sun rose in the
early morning hours of 2000 August 12,
meteors pelted the Earth from the direction of the constellation
Perseus, while
ions
pelted the Earth from the
Sun.
The
meteors were expected as sub-sand grains long left behind by
Comet Swift-Tuttle annually create the
Perseids Meteor Shower.
The aurorae
were unexpected, however, as
electrons,
protons, and
heavier ions raced out from a large
Coronal Mass Ejection that had
occurred just days
before on the Sun.
In the foreground is Hahn's Peak, an extinct volcano in
Colorado,
USA.
The Perseid meteor shower peaks this year over the next few days,
with as much as one bright
meteor per minute visible from some locations.
APOD: 2003 May 5 - NGC 1275: A Galactic Collision
Explanation:
In NGC 1275, one galaxy is slicing through another.
The disk of the
dusty
spiral galaxy
near the image center is cutting through a large
elliptical galaxy,
visible predominantly on the lower left.
Galaxies can change significantly during a
collision like this, with
gravitational tides
distorting each galaxy and
gas clouds being
compressed and lighting up with new
star formation.
Galaxy collisions
occur in slow motion to the
human eye, with a single pass taking as much as 100 million years.
NGC 1275 is a member of the
Perseus cluster of galaxies
that lies about 230 million light years away toward the constellation of
Perseus.
Each galaxy spans about 50,000 light years across.
The above picture is a composite of
images taken by the
Hubble Space Telescope in 1995 and 2001.
APOD: 2002 August 15 - Meteors and Northern Lights
Explanation:
Skygazers report
that the annual Perseid meteor shower
went pretty much as predicted,
producing a meteor
every few minutes during the dark early morning hours
of August 12 and 13.
And as the
constellation Perseus
rose above the horizon on the night of August 11,
astrophotographer Wade Clark was anticipating
recording images of the flashing meteor trails
from the Mt. Baker Ski Area in northwest Washington, USA.
But Clark was also treated to a colorful display of
northern lights.
As a result, the stars
of Perseus
are arrayed near the center
of his well composed skyscape along with trails
of Perseid meteors
all viewed
through the auroral glow.
The alluring scene might look familiar to watchers of
bygone Perseids.
For many, views of the meteor shower
in 2000 also coincided with
auroral displays, courtesy of the
active Sun.
APOD: 2002 August 11 - A Perseid Meteor
Explanation:
The ongoing
Perseid
Meteor Shower should be at its strongest on August 12 and 13.
The best time to watch will be between 2:00 AM and dawn on Monday
morning (so plan on setting your alarm tonight!)
and then again on Tuesday.
In dark, moonless, predawn
skies you may see dozens of meteors per hour.
Grains of cosmic sand and gravel shed from
Comet Swift-Tuttle will
streak across the sky as they vaporize during entry into Earth's
atmosphere.
Tracing the meteor
trails backwards,
experienced skygazers will find they converge
on the constellation Perseus, thus this
annual meteor shower's name.
Pictured
above is a Perseid meteor from 1993.
The colors are representative but digitally enhanced.
As the
meteor streaked across the night sky,
different excited atoms emitted different colors of light.
The origin of the green tinge visible at the right is currently unknown,
however, and might result from
oxygen
in Earth's atmosphere.
APOD: 2001 August 10 - Perseids of Summer
Explanation:
Like falling
stardust,
cast off bits of comet
Swift-Tuttle hurtle through
the upper atmosphere about this time each year as planet Earth passes
near the comet's orbital path.
For the northern hemisphere, this
regular
celestial display is known as the annual
Perseid
meteor shower -- so named because the meteor trails
all appear traceable to a common "radiant point" in the
constellation Perseus.
This gorgeous wide-angle
photo from the 1997 shower
captures a
20-degree-long
fireball meteor
and another, fainter Perseid
meteor trail in a rich area of the northern
summer Milky Way.
A labeled version
is available identifying
the shower's radiant point,
surrounding deep-sky objects, and constellations.
Easy to view (just go outside and look up!), the
Perseid meteor
shower will peak this weekend with maximum rates anticipated
early Sunday morning, August 12, for eastern North America.
Despite interfering moonlight,
last year's faithful
Perseid watchers
were rewarded with bright meteors and extensive displays of
the
northern lights.
APOD: 2001 March 2 - LkHa101: The Hole in the Doughnut
Explanation:
You'd need a really big cup of
coffee with this doughnut ...
because the hole in the middle is about a billion kilometers
across.
Centered on the Sun, a circle that size would lie
between the orbits of Mars and Jupiter.
In fact, this doughnut is known to surround a massive newborn star
cataloged as LkHa 101
which lies in the
constellation Perseus.
Imaged
in infrared light, the tantalizing torus-shaped cloud of gas
and dust
is slightly tilted to our view.
The cloud's material may well be the ingredients
for the formation of a
distant
solar system.
A bright source of
ultraviolet light,
the hot young star itself is much fainter in the
infrared and so not visible in this picture.
Still, the star's presence is indicated as its intense stellar wind and
radiation has apparently carved out the doughnut's hole.
This premier close-up of a stellar system in formation was accomplished
by adapting a powerful observational technique
called
interferometry to planet Earth's largest single mirror
telescope, the 10 meter Keck.
APOD: 2000 October 31 - The Perseus Cluster s X Ray Skull
Explanation:
This haunting image from the orbiting
Chandra Observatory
reveals the Perseus Cluster of Galaxies
in x-rays,
photons with a thousand or more times the energy of visible light.
Three hundred twenty million light-years distant, the
Perseus Cluster
contains thousands of galaxies, but none of them are
seen here.
Instead of mere galaxies, a fifty million degree cloud of
intracluster gas, itself more
massive than all the cluster's galaxies
combined, dominates the x-ray view.
From this angle, voids and bright knots in the
x-ray hot gas cloud lend it a very
suggestive appearance.
Like eyes in a skull, two dark bubbles flank a bright central source
of x-ray emission.
A third elongated bubble (at about 5 o'clock) forms a toothless mouth.
The bright x-ray source is likely a supermassive black hole at the
cluster center with the bubbles blown by explosions of
energetic particles ejected from the black hole and expanding into
the immense gas cloud.
Fittingly, the dark spot forming the skull's "nose" is an
x-ray shadow ... the shadow of a large galaxy inexorably falling into
the cluster center.
Over a hundred thousand light-years across, the Perseus Cluster's
x-ray skull is a bit larger than skulls you
may see tonight.
Have a safe and happy Halloween!
APOD: 2000 August 21 - A Perseid Aurora
Explanation:
Just after the
Moon set but before the
Sun rose in the
early morning hours of August 12,
meteors pelted the Earth from the direction of the constellation
Perseus, while
ions
pelted the Earth from the
Sun.
The
meteors were expected as sub-sand grains long left behind by
Comet Swift-Tuttle annually create the
Perseids Meteor Shower.
The aurorae
were unexpected, however, as
electrons,
protons, and
heavier ions raced out from a large
Coronal Mass Ejection that had
occurred just days
before on the Sun.
In the foreground is Hahn's Peak, an extinct volcano in
Colorado,
USA.
APOD: 2000 June 15 - X-Rays From The Perseus Cluster Core
Explanation:
The Perseus Cluster
of thousands of galaxies, 320 million
light-years distant, is
one of
the most massive objects
in
the Universe.
At its core lies the giant cannibal galaxy
Perseus A
(NGC 1275), accreting matter as
gas and galaxies fall into it.
Representing low, medium, and high energy
x-rays as red, green,
and blue colours respectively,
this Chandra X-ray Observatory image
shows remarkable details of x-ray emission from this monster galaxy and
surrounding hot (30-70 million degrees C)
cluster gas.
The bright central source is the supermassive
black
hole at the core of Perseus A itself.
Dark circular voids just above and below the galaxy center,
each about half the size of our own
Milky Way Galaxy,
are believed to be magnetic bubbles of
energetic particles
blown by the accreting black hole.
Settling
toward
Perseus A, the cluster's x-ray hot gas piles up
forming bright regions around the bubble rims.
Dramatically, the long greenish wisp just above the galaxy's centre
is likely the x-ray shadow produced by
a small galaxy falling into the burgeoning
Perseus A.
APOD: August 15, 1998 - The Perseus Cluster of Galaxies
Explanation:
Here is one of
the largest objects that anyone will ever see on the sky.
Each of the fuzzy blobs in the above picture is a galaxy, together
making up the Perseus Cluster, one of the closest
clusters of galaxies.
We view the cluster through the foreground of faint stars in our own
Milky Way Galaxy.
It takes light roughly 300 million years to get here
from this region of
the Universe, so we
see this cluster as it existed before
the age of the dinosaurs.
Also known as
Abell 426, the center of the Perseus Cluster
is a prodigious source of
X-ray radiation, and so helps
astronomers explore
how clusters formed and
how gas and
dark matter interact.
The Perseus Cluster of Galaxies is part of the
Pisces-Perseus
supercluster of galaxies,
which spans over 15 degrees and contains over 1000
galaxies.
APOD: January 26, 1998 - Interplanetary Spaceship Passes Earth
Explanation:
Last Thursday an interplanetary spacecraft flew right past the Earth.
The
above images
show sunlight momentarily
reflected from this spacecraft's solar panels.
No aliens were involved - the
Near Earth Asteroid Rendezvous (NEAR)
mission actually originated from Earth. Launched in 1996,
NEAR
zipped past the asteroid
253 Mathilde
last June. This
Earth flyby gravitationally deflects NEAR onto a trajectory
passing the asteroid 433 Eros next year.
Above, NEAR appears to move through the constellation of
Perseus, as
clouds created a changing diffuse white glow.
NEAR was only visible for about 2 minutes from
San Jose, California,
where these image-intensified video camera observations were taken.
APOD: December 25, 1997 - A Hale Bopp Holiday
Explanation:
Seen from the
Pik Terskol Observatory in the
northern Caucasus mountains,
comet Hale-Bopp and the bright
stars of
the constellation Perseus
hang above the snowy,
moon-lit landscape.
Although it reminds
Northern Hemisphere dwellers of an idyllic
Winter scene,
this picture was actually recorded in the spring -
on April 13th of this year.
Seasons Greetings and Best Wishes from
APOD!
APOD: April 26, 1997 - The Perseus Cluster of Galaxies
Explanation: Here is one of the largest objects that anyone
will ever see on the sky. Each of the fuzzy blobs in the above
picture is a galaxy, together making
up the Perseus Cluster,
one of the closest clusters of galaxies.
We view the cluster through the foreground of faint stars in our
own Milky Way Galaxy. It takes light
roughly 300 million years to get here from there, so we only see
this cluster as it existed during the age of the dinosaurs. Also
known as Abell 426, the center of Perseus cluster is a prodigious
source of X-ray radiation, and so
helps astronomers study how clusters formed and how gas
and dark matter
interact. The Perseus Cluster of Galaxies is part of the Pisces-Perseus supercluster
of galaxies, which spans over 15 degrees and contains over 1000
galaxies.
APOD: April 16, 1997 - A Star Cluster Through Hale-Bopp's Tail
Explanation: Comet Hale-Bopp continues to look impressive.
The photograph above
captured the comet on April 7th passing nearly in front
of M34,
a star cluster in the constellation of Perseus.
Many of the stars in this open cluster
can be seen through Comet Hale-Bopp's
white dust tail. The bright blue ion tail
now shows several streams. Now receding
from both the Sun and the Earth, Comet Hale-Bopp
should still remain an impressive sight
for weeks to come as it slowly fades.
APOD: January 29, 1997 - NGC 869 & NGC 884: A Double Open Cluster
Explanation: Most star clusters are singularly impressive.
But open clusters NGC 869 and NGC 884
are doubly impressive. Also known as "h and chi Persei",
this rare double cluster, shown above,
is bright enough to be seen from a dark location without even
binoculars. Although their discovery surely predates written
history, the "double cluster" was notably cataloged
by the Greek astronomer Hipparcos.
The clusters are over 7000 light years distant toward the constellation
of Perseus,
but are separated by only hundreds of light years.
APOD: August 9, 1996 - The Perseid Meteor Shower
Explanation:
From a radiant point in the constellation of Perseus, Comet Swift-Tuttle
presents -- The Perseid Meteor Shower -- coming to your night sky this weekend!
A bookish E. C. Herrick of New Haven, Connecticut correctly suspected in 1837 that
this meteor shower was an annual event.
Indeed it is now known to be a
regular August shower caused by the
yearly passage of the Earth through the orbiting debri left behind
by periodic comet Swift-Tuttle.
Since the bits of comet debri are
moving along parallel orbits, on entering the atmosphere they leave
fiery trails which appear to originate
from a common radiant point
in the sky, in this case in the
constellation of Perseus.
Dramatically illustrated in this
composite video image made using
MOVIE,
meteors from the 1994 Perseids
streak across the sky framed by the three bright stars of the
asterism known as the "Summer Triangle".
The image shows
bright Perseids recorded that year
from August 9 through 14. Here the trails appear nearly parallel as the camera
was centered on the sky about 90 degrees from the radiant point.
This year,
European and North American observers should be able
to view the shower near its maximum, about 90 meteors per hour,
early Monday morning August 12, but the shower should be enjoyable
on clear weekend nights (August 10,11) as well.
After midnight is generally the best time for viewing.
What's the best way to enjoy a meteor shower?
Get a warm jacket and a comfortable lawnchair ...
go outside and look up.
APOD: April 23, 1996 - Comet Hyakutake on a Starry Night
Explanation:
It was a starry night in April
(April 9th, 1996, 9:32 pm CDT to be exact)
near Lone Jack, Missouri when Comet Hyakutake graced
this astronomically rich field. Making an appearance as the
brilliant evening star, Venus
is overexposed at the far left.
Just below Venus and slightly to the right,
the Pleiades star cluster (M45) glistens.
On the right hand
side of the image, the comet itself shows
a bright blue tail extending
upwards past the nearby star cluster in
the constellation Perseus (top right, the Alpha Persei Group).
Hyakutake, receding from
the Earth and appoaching the Sun, will sink into the western horizon
at sunset in
late April,
disappearing from Northern Hemisphere skies.
APOD: April 5, 1996 - The Perseus Cluster of Galaxies
Explanation:
Here is one of the largest objects that anyone will ever see on the
sky. Each of the fuzzy blobs in the above picture is a
galaxy, together making up the Perseus Cluster,
one of the closest
clusters
of galaxies.
We view the cluster through the foreground of faint stars in our own
Milky Way galaxy.
It takes light roughly 300 million years to get here from there, so we only
see this cluster as it existed during the age of the dinosaurs. Also known
as Abell 426, the center of Perseus cluster is a prodigious
source of X-ray radiation,
and so helps us study how
clusters formed and how
gas and
dark
matter interact.
The Perseus Cluster of Galaxies is part of the Pisces-Perseus supercluster
of galaxies, which spans over 15 degrees and contains over 1000 galaxies.