Astronomers
of
Verde Valley
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Images from club member Steve Leshin. As of August 1st, 2013, Steve has had
17 of his images posted on NASA's Astronomy Photo of the Day. (APOD) Images
courtesy of Steve Leshin.
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Astronomical pictures are not just point and shoot. Special, very
sensitive CCD cameras are used to create a photo that is monochrome or black and
white. The color is created by using different filters on the camera and
assigning each picture to a color channel using software.
The pictures to the left and below show the different filters
to create the picture above.
The picture at left is the Luminance Channel of the picture.
Exposure time:5.3 hours |
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The picture at left is the H-Alpha Channel of the picture.
Exposure time:7 hours |
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The picture at left is the Red, Green and Blue color channels
combined. Exposure time: 19.5 hours
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Adding the Luminance Channel to the RGB image
brings the exposure up to 23.8 hours |
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Combing all the images from the different filter channels
gives a LHaRGB image for a total of 31.8 hours Click the picture to
enlarge |
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APOD: 2013 October 20 Three Galaxies in Draco
Explanation: This intriguing
trio of galaxies is sometimes called the Draco Group, located in the northern
constellation of (you guessed it)
Draco. From left
to right are edge-on spiral
NGC 5981, elliptical galaxy
NGC 5982, and face-on spiral
NGC 5985 -- all within this single telescopic field of view spanning a little
more than half the width of the full moon. While the group is far too small to
be a galaxy cluster and
has not been catalogued
as a compact group, these galaxies all do lie roughly 100 million light-years
from planet Earth. On close examination with
spectrographs, the bright core of the striking face-on spiral NGC 5985 shows
prominent emission in specific wavelengths of light, prompting astronomers to
classify it as a
Seyfert,
a type of active galaxy. Not as well known as other tight
groupings of galaxies, the
contrast in visual appearance makes this triplet an attractive subject for
astrophotographers. This
impressively deep exposure hints at faint, sharp-edged shells surrounding
elliptical NGC 5982, evidence of past galactic mergers. It also reveals many
even more distant
background
galaxies.
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APOD: 2013 July 18 - Hidden Galaxy IC 342
Explanation: Similar
in size to large, bright spiral galaxies in our neighborhood,
IC 342 is a mere
10 million light-years
distant in the long-necked, northern constellation
Camelopardalis. A
sprawling island universe,
IC 342 would otherwise be a prominent galaxy in our
night sky, but it is
hidden from clear view and only glimpsed through the veil of stars, gas and dust
clouds along the plane of our own
Milky Way galaxy. Even
though IC 342's light is dimmed by intervening
cosmic clouds, this
deep telescopic image traces the galaxy's obscuring dust, blue star
clusters, and glowing pink star forming regions along spiral arms that wind far
from the galaxy's core. IC 342 may have undergone a recent
burst of star formation
activity and is close
enough to have gravitationally influenced the evolution of the
local group of galaxies
and the Milky Way.
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APOD: 2013 February 8 - NGC 6822: Barnard's Galaxy
Explanation: Grand
spiral galaxies often seem to get all the glory, flaunting their young,
bright, blue star clusters in beautiful, symmetric spiral arms. But small
galaxies form stars too, like nearby NGC 6822, also known as
Barnard's Galaxy.
Beyond the rich starfields in the constellation Sagittarius,
NGC 6822 is a mere 1.5
million light-years away, a member of our
Local Group of
galaxies. About 7,000 light-years across, the dwarf irregular galaxy is seen to
be filled with young blue stars and mottled with the telltale pinkish hydrogen
glow of star forming regions
in the deep
color composite image. Contributing to the science of
LITTLE THINGS, this
portrait of a small galaxy was made as part of the
Lowell Amateur Research
Initiative (LARI), welcoming collaborations with amateur astronomers.
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APOD: 2012 October 31 - VdB 152: A Ghost in Cepheus
Explanation: Described as a "dusty curtain" or "ghostly
apparition", mysterious reflection nebula VdB 152 really is very faint. Far from
your neighborhood on this
Halloween Night, the cosmic phantom is nearly 1,400 light-years away. Also
catalogued as Ced 201, it lies along the
northern Milky Way in the royal
constellation Cepheus.
Near the edge of a large molecular cloud, pockets of interstellar dust in the
region block light from background stars or scatter light from the embedded
bright star giving parts of
the nebula a
characteristic blue color.
Ultraviolet light from the star is also
thought to cause a dim reddish
luminescence in the
nebular dust. Though stars do form in
molecular clouds, this star seems to have only accidentally wandered into
the area, as its measured velocity through space is very different from the
cloud's velocity. This
deep telescopic image of the region spans about 7 light-years.
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APOD: 2012 June 22 - IC 2574: Coddington's Nebula
Explanation: Grand
spiral galaxies often seem to get all the glory, flaunting their young,
bright, blue star clusters in beautiful, symmetric
spiral arms. But small,
irregular galaxies form stars too. In fact
dwarf galaxy IC 2574 shows clear
evidence of intense star forming activity in its telltale pinkish regions of
glowing hydrogen gas. Just as in spiral galaxies, the
turbulent star-forming regions
in IC 2574 are churned by
stellar winds and supernova explosions spewing material into the galaxy's
interstellar medium and
triggering further star formation. A mere 12 million light-years distant, IC
2574 is part of the M81 group of galaxies, seen toward the northern
constellation Ursa Major. Also known as Coddington's Nebula, the lovely
island universe is about
50,000 light-years across, discovered by American astronomer Edwin Coddington in
1898.
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APOD: 2012 February 16 - NGC 5965 and NGC 5963 in Draco
Explanation: These two spiral galaxies make a photogenic pair, found
within the boundaries of the northern
constellation
Draco. Contrasting in color and orientation, NGC 5965 is
nearly edge-on to our line
of sight and dominated by yellow hues, while bluish NGC 5963 is closer
to face-on. Of course,
even in this
well-framed cosmic snapshot the scene is invaded by other galaxies,
including small elliptical NGC 5969 at the lower left. Brighter, spiky stars in
our own Milky Way are scattered through the foreground. Though they seem to be
close and of similar size, galaxies NGC 5965 and NGC 5963 are far apart and
unrelated, by chance
appearing
close on the sky. NGC
5965 is about 150 million light-years distant and over 200,000 light-years
across. Much smaller, NGC 5963 is a mere 40 million light-years away and so is
not associated with the edge-on spiral. Difficult to follow, NGC 5963's
extraordinarily faint blue spiral arms
mark it as a
low surface brightness galaxy.
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APOD: 2011 November 4 - Edge on NGC 3628
Explanation: Sharp telescopic views of magnificent edge-on spiral
galaxy NGC 3628 show a
puffy galactic disk
divided by dark dust lanes. The tantalizing scene puts many astronomers
in mind of its popular
moniker, The Hamburger Galaxy. About 100,000 light-years across and 35 million
light-years away in the constellation Leo, NGC 3628 shares its neighborhood in
the local Universe
with two other large spirals, a grouping otherwise known as
the Leo Triplet.
Gravitational interactions with its cosmic neighbors are likely responsible for
the extended flare and warp of this spiral's disk, populated by the galaxy's
young blue star clusters
and tell tale pinkish star forming regions. Also a result of past close
encounters, a faint
tidal tail
of material is just visible extending upward and left in
this deep galaxy portrait.
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APOD: 2011 August 29 - Hickson 44 in Leo
Explanation: Scanning the skies for galaxies, Canadian astronomer Paul
Hickson and colleagues identified some 100 compact
groups of galaxies, now appropriately called
Hickson
Compact Groups. The four prominent galaxies seen in this intriguing
telescopic skyscape are one such group, Hickson 44, about 100 million
light-years distant toward the constellation Leo. The two spiral galaxies in the
center of the image are edge-on NGC 3190 with its distinctive, warped dust
lanes, and S-shaped NGC 3187. Along with the bright elliptical, NGC 3193 at the
right, they are also known as Arp 316. The spiral in the upper left corner is
NGC 3185, the 4th member of the Hickson group. Like other galaxies in Hickson
groups, these show signs of distortion and
enhanced star formation,
evidence of a gravitational tug of war that will eventually result in
galaxy mergers
on a cosmic timescale. The merger process is now understood to be a normal part
of the evolution of galaxies, including
our own Milky Way. For
scale, NGC 3190 is about
75,000 light-years across at the estimated distance of Hickson 44
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APOD: 2011 July 7 - Arp 78: Peculiar Galaxy in Aries
Explanation:
Peculiar spiral
galaxy Arp 78 is found within the boundaries of the head strong
constellation Aries,
some 100 million light-years
beyond the stars and nebulae of our Milky Way galaxy. Also known as NGC 772,
the island universe is over 100 thousand light-years across and sports a single
prominent outer spiral arm in
this detailed
cosmic portrait. Its brightest
companion
galaxy, compact NGC 770, is toward the upper right of the larger spiral. NGC
770's fuzzy, elliptical appearance contrasts nicely with a spiky foreground
Milky Way star in matching yellowish hues. Tracking along sweeping dust lanes
and lined with young blue star
clusters, Arp 78's large spiral arm is likely due to gravitational tidal
interactions.
Faint streams of material seem to connect Arp 78 with its nearby companion
galaxies.
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APOD: 2011 February 26 - Shell Galaxies in Pisces
Explanation: This
colorful cosmic skyscape features a peculiar system of galaxies
cataloged as
Arp 227 some 100 million light-years distant.
Swimming within
the boundaries of the
constellation Pisces, Arp 227 consists of the two galaxies
prominent on the left; the curious shell galaxy NGC 474 and its blue,
spiral-armed neighbor NGC 470. The faint, wide arcs or
shells of NGC 474
could have been formed by a gravitational encounter with neighbor NGC 470.
Alternately the shells could be
caused by a merger with a
smaller galaxy producing an effect analogous to ripples across the surface of a
pond. Remarkably, the large galaxy on the right hand side of the deep image, NGC
467, appears to be surrounded by faint shells too, evidence of another
interacting galaxy
system. Intriguing background galaxies are scattered around the field that also
includes
spiky foreground stars. Of course, those stars lie well within our own
Milky Way Galaxy. The
field of view spans 25 arc minutes or about 1/2 degree
on the sky.
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APOD: 2010 August 13 - Arp 286: Trio in Virgo
Explanation: A remarkable telescopic composition in yellow and blue,
this scene features a trio of interacting galaxies almost 90 million
light-years away, toward the
constellation Virgo.
On the left, two,
spiky, foreground Milky Way stars echo the trio galaxy hues, a reminder that
stars in our own galaxy are like those in the distant
island universes.
Predominately yellow, with sweeping spiral arms and dust lanes, NGC 5566 is
enormous, about 150,000 light-years across. Just below it lies small, blue NGC
5569. Near center, the third galaxy, NGC 5560, is multicolored and apparently
stretched and distorted by its interaction with NGC 5566. The galaxy trio is
also included in Halton Arp's 1966
Atlas of
Peculiar Galaxies as Arp 286. Of course, such
cosmic
interactions are now
appreciated as a common part of the
evolution of galaxies.
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APOD: 2010 April 29 - Virgo Cluster Galaxy NGC 4731
Explanation: Barred spiral galaxy NGC 4731 lies some 65 million
light-years away. The lovely island universe resides in the large
Virgo cluster of
galaxies. Colors in this
well-composed, cosmic portrait, highlight plentiful, young, bluish
star clusters along the
galaxy's
sweeping spiral arms. Its broad arms are distorted by gravitational
interaction with a
fellow Virgo
cluster member, giant elliptical galaxy NGC 4697. NGC 4697 is beyond this
frame above and to the left, but a smaller irregular galaxy NGC 4731A can be
seen near the bottom in impressive detail with its own young blue star clusters.
Of course, the individual, colorful,
spiky stars in the scene
are much closer, within our
own Milky Way galaxy.
NGC 4731 itself
is well over 100,000 light-years across.
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APOD: 2006 August 15 - IC 410 and NGC 1893
Explanation: A faint, dusty rose of the northern sky, emission nebula IC
410 lies about 12,000 light-years away in the constellation
Auriga. The cloud of
glowing hydrogen gas is over 100 light-years across,
sculpted by
stellar winds
and radiation from embedded open star cluster NGC 1893.
Formed in
the interstellar cloud a mere
4 million years ago, bright cluster stars are seen just below the prominent
dark dust cloud near
picture center. Notable near the 7 o'clock position in this wide, detailed view
are two relatively dense streamers of material trailing away from the nebula's
central regions. Potentially sites of ongoing star formation, these
cosmic tadpole shapes are
about 10 light-years long.
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The Pinwheel Galaxy
Also known as the Triangulum Galaxy & Messier
33 (M33) is a member of the Local Group of galaxies including the Milky Way and
the Andromeda Galaxy. It is a close 3 million light years away in the
constellation Triangulum. One theory suggests that it may be moving towards the
Milky Way Galaxy and may precede the arrival of the Andromeda Galaxy. This is
what it might look like as it closes in on the Milky Way in several billion
years. M33 is one of the handful of galaxies that may be seen without aid to the
eye from a dark site. |
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Pac Man Nebula
Also known as the NGC 281, this nebula is an H
II Region in the constellation Cassiopeia. Discovered in 1883 by E. E. Barnard,
the name Pac Man was obviously tagged to the object in the 1980's after the
popular video game. The star cluster IC 1590 makes up the eye of the Pac Man.
Several Bok Globules can also be seen in the nebula. These are the dark bubble
shaped and column shaped clouds of dust. |
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ARP 104 Galaxies
Entry number 104 in the Halton Arp Atlas of
Peculiar Galaxies is located in the constellation of Ursa Major, also known as
the Big Dipper. A mere distance of 22,000 light years separates the two
galaxies. A bridge of stellar material connects the two. These galaxies are also
know as NGC 5216 and NGC 5218. William Herschel first discovered the galaxies in
1790 and they were studied by Edwin Hubble in 1926. Sometimes called Keenan's
System, Philip Keenan published a paper in 1935 about the bridge connecting the
galaxies. |
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