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NASA Galaxies
Pictures June-October 2009
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Stars at
the Galactic Center
The center
of our Milky Way Galaxy is hidden from the prying eyes of
optical telescopes by clouds of obscuring dust and gas. But, in
this stunning vista, the Spitzer Space Telescope's infrared
cameras penetrate much of the dust, revealing the stars of the
crowded galactic center region. A mosaic of many smaller
snapshots, this detailed, false-color image shows older, cool
stars in bluish hues. Reddish glowing dust clouds are associated
with young, hot stars in stellar nurseries. The galactic center
lies some 26,000 light-years away, toward the constellation
Sagittarius. At that distance, this picture spans about 900
light-years.
A
Super-Efficient Particle Accelerator
This image, created from data obtained from NASA's Chandra X-ray
Observatory and the European Southern Observatory's Very Large
Telescope, shows a part of the roughly circular supernova
remnant known as RCW 86. This remnant of an exploded star may be
the one observed in 185 AD by Chinese astronomers. By studying
it, astronomers gained a better understanding of new details
about the role of supernova remnants as the Milky Way's
super-efficient
particle accelerators.
M1: The
Crab Nebula from Hubble
Credit:
NASA, ESA, J. Hester, A. Loll (ASU); Acknowledgement: Davide De
Martin (Skyfactory)
Explanation: This is the mess that is left when a star explodes.
The Crab Nebula, the result of a supernova seen in 1054 AD, is
filled with mysterious filaments. The filaments are not only
tremendously complex, but appear to have less mass than expelled
in the original supernova and a higher speed than expected from
a free explosion. The above image, taken by the Hubble Space
Telescope, is presented in three colors chosen for scientific
interest. The Crab Nebula spans about 10 light-years. In the
nebula's very center lies a pulsar: a neutron star as massive as
the Sun but with only the size of a small town. The Crab Pulsar
rotates about 30 times each second.
Martian
Dust Devil Trails
Credit: HiRISE, MRO, LPL (U. Arizona), NASA
Explanation: Who's been marking up Mars? This portion of a
recent high-resolution picture from the HiRISE camera on board
the Mars Reconnaissance Orbiter shows twisting dark trails criss-crossing
light colored terrain on the martian surface. Newly formed
trails like these had presented researchers with a tantalizing
martian mystery but are now known to be the work of miniature
wind vortices known to occur on the red planet - martian dust
devils. Such spinning columns of rising air heated by the warm
surface are also common in dry and desert areas on planet Earth.
Typically lasting only a few minutes, dust devils become visible
as they pick up loose red-colored dust leaving the darker and
heavier sand beneath intact. On Mars, dust devils can be up to 8
kilometers high. Dust devils have been credited with unexpected
cleanings of mars rover solar panels.
Pleiades
and Stardust
Credit &
Copyright: Rogelio Bernal Andreo (Deep Sky Colors)
Explanation: Have you ever seen the Pleiades star cluster?
Perhaps the most famous star cluster on the sky, the Pleiades
can be seen without binoculars from even the depths of a
light-polluted city. Also known as the Seven Sisters and M45,
the Pleiades is one of the brightest and closest open clusters.
Hurtling through a cosmic dust cloud a mere 400 light-years
away, the Pleiades or Seven Sisters star cluster is well-known
for its striking blue reflection nebulae. This remarkable
wide-field (3 degree) image of the region shows the famous star
cluster near the center, while highlighting lesser known dusty
reflection nebulas nearby, across an area that would span over
20 light-years. In this case, the sister stars and cosmic dust
clouds are not related, they just happen to be passing through
the same region of space.
The Lagoon
Nebula from GigaGalaxy Zoom
Credit:
ESO
Explanation: The large majestic Lagoon Nebula is home for many
young stars and hot gas. Spanning 100 light years across while
lying only about 5000 light years distant, the Lagoon Nebulae is
so big and bright that it can be seen without a telescope toward
the constellation of Sagittarius. Many bright stars are visible
from NGC 6530, an open cluster that formed in the nebula only
several million years ago. The greater nebula, also known as M8
and NGC 6523, is named "Lagoon" for the band of dust seen to the
left of the open cluster's center. A bright knot of gas and dust
in the nebula's center is known as the Hourglass Nebula. The
above picture is a newly released, digitally stitched panorama
of M8 taken as part of the GigaGalaxy Zoom project by the Wide
Field Imager attached to the MPG/ESO 2.2-meter Telescope at the
La Silla Observatory in Chile. The vista spans three times the
diameter of the Moon, while the highest resolution image version
occupies over 350 million pixels. Star formation continues in
the Lagoon Nebula as witnessed by the many globules that exist
there.
Orion in
Gas, Dust, and Stars
Credit &
Copyright: Rogelio Bernal Andreo (Deep Sky Colors)
Explanation: The constellation of Orion holds much more than
three stars in a row. A deep exposure shows everything from dark
nebula to star clusters, all imbedded in an extended patch of
gaseous wisps in the greater Orion Molecular Cloud Complex. The
brightest three stars on the far left are indeed the famous
three stars that make up the belt of Orion. Just below Alnitak,
the lowest of the three belt stars, is the Flame Nebula, glowing
with excited hydrogen gas and immersed in filaments of dark
brown dust. Below the frame center and just to the right of
Alnitak lies the Horsehead Nebula, a dark indentation of dense
dust that has perhaps the most recognized nebular shapes on the
sky. On the upper right lies M42, the Orion Nebula, an energetic
caldron of tumultuous gas, visible to the unaided eye, that is
giving birth to a new open cluster of stars. Immediately to the
left of M42 is a prominent bluish reflection nebula sometimes
called the Running Man that houses many bright blue stars. The
above image, a digitally stitched composite taken over several
nights, covers an area with objects that are roughly 1,500 light
years away and spans about 75 light years.
Gigagalaxy Zoom: Galactic Center
Credit: ESO / Stéphane Guisard - Copyright: Stéphane Guisard
Explanation: From Sagittarius to Scorpius, the central Milky Way
is a truly beautiful part of planet Earth's night sky. The
gorgeous region is captured here, an expansive gigapixel mosaic
of 52 fields spanning 34 by 20 degrees in 1200 individual images
and 200 hours of exposure time. Part of ESO's Gigagalaxy Zoom
Project, the images were collected over 29 nights with a small
telescope under the exceptionally clear, dark skies of the ESO
Paranal Observatory in Chile. The breathtaking cosmic vista
shows off intricate dust lanes, bright nebulae, and star
clusters scattered through our galaxy's rich central starfields.
Starting on the left, look for the Lagoon and Trifid nebulae,
the Cat's Paw, the Pipe dark nebula, and the colorful clouds of
Rho Ophiuchi and Antares
This image
of the core of the nearby spiral galaxy M51, taken with the Wide
Field Planetary camera (in PC mode) on NASA's Hubble Space
Telescope, shows a striking , dark "X" silhouetted across the
galaxy's nucleus. The "X" is due to absorption by dust and marks
the exact position of a black hole which may have a mass
equivalent to one-million stars like the sun. The darkest bar
may be an edge-on dust ring which is 100 light-years in
diameter. The edge-on torus not only hides the black hole and
accretion disk from being viewed directly from earth, but also
determines the axis of a jet of high-speed plasma and confines
radiation from the accretion disk to a pair of oppositely
directed cones of light, which ionize gas caught in their beam.
The second bar of the "X" could be a second disk seen edge on,
or possibly rotating gas and dust in MS1 intersecting with the
jets and ionization cones.
The size
of the image is 1100 light-years.
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