Down on the River by David Cartier on Flickr.
Stephan’s Quintet
Image Data: Hubble Legacy Archive, ESA, NASA; Processing: Al KellyExplanation: The first identified compact galaxy group, Stephan’s Quintet is featured in this eye-catching image constructed with data drawn from the extensive Hubble Legacy Archive. About 300 million light-years away, only four of these five galaxies are actually locked in a cosmic dance of repeated close encounters. The odd man out is easy to spot, though. The interacting galaxies, NGC 7319, 7318A, 7318B, and 7317 have an overall yellowish cast. They also tend to have distorted loops and tails, grown under the influence of disruptive gravitational tides. But the predominantly bluish galaxy, NGC 7320, is closer, just 40 million light-years distant, and isn’t part of the interacting group. Stephan’s Quintet lies within the boundaries of the high flying constellation Pegasus. At the estimated distance of the quartet of interacting galaxies, this field of view spans about 500,000 light-years. However, moving just beyond this field, above and to the left, astronomers can identify another galaxy, NGC 7320C, that is also 300 million light-years distant. Of course, including it would bring the interacting quartet back up to quintet status.
NASA APOD 25 Feb 2012
Aurigae Nebulae
Image Credit & Copyright: Steve Cannistra (StarryWonders)Explanation: Rich in star clusters and nebulae, the ancient constellation of Auriga, the Charioteer, rides high in northern winter night skies. Composed from narrow and broadband filter data and spanning nearly 8 Full Moons (4 degrees) on the sky, this deep telescopic view recorded in January shows off some of Auriga’s celestial bounty. The field includes emission region IC 405 (top left) about 1,500 light-years distant. Also known as the Flaming Star Nebula, its red, convoluted clouds of glowing hydrogen gas are energized by hot O-type star AE Aurigae. IC 410 (top right) is significantly more distant, some 12,000 light-years away. The star forming region is famous for its embedded young star cluster, NGC 1893, and tadpole-shaped clouds of dust and gas. IC 417 and NGC 1931 at the lower right, the Spider and the Fly, are also young star clusters embedded in natal clouds that lie far beyond IC 405. Star cluster NGC 1907 is near the bottom edge of the frame, just right of center. The crowded field of view looks along the plane of our Milky Way galaxy, near the direction of the galactic anticenter.
NASA APOD, 24 Feb 2012
Earth’s Shadow on the Moon
by: Nathaniel Custodio (tani), Taguig City, Philippines, December 10 2011
AAPOD, 24 Feb 2012
Water! 140 Trillion Times Earth’s Oceans—Surrounds a Voracious Black Hole at the Edge of the Universe!
Read more here.
Source: Milky way scientists
NASA’s water discovery should be a reminder that if we have the sophistication to discover galaxies full of water 12 billion light years away, we should be able to save people just an ocean away from drought-induced starvation.
Spectacularly bright object in Andromeda caused by ‘normal’ black hole
provided by Royal Astronomical Society
An international team of scientists, led by Dr. Matt Middleton, of Durham University, analysed the Ultraluminous X-ray Source (ULX), which was originally discovered in the Andromeda galaxy by NASA’s Chandra x-ray observatory. They publish their results in the journals Monthly Notices of the Royal Astronomical Society and Astronomy and Astrophysics.
Many ULXs are too far away for astronomers to study, but the relatively close proximity of Andromeda to the Milky Way – around 2.5 million light years – gave the team opportunity to study the phenomenon. The researchers say their study could begin to answer the question about what causes ULXs. Some scientists believe they are caused by relatively small black holes, a few times the mass of our Sun. These black holes rapidly pull in gas and dust which forms an “accretion disc” and heats up causing the material to emit X-rays.
Other scientists say ULXs are caused by material being dragged in by an intermediate-sized black hole formed from the merger of many stellar black holes with a mass perhaps 1,000 times bigger than the Sun. The Durham-led findings link the ULX spotted in Andromeda to a normal stellar black hole formed after a massive star exploded as a supernova…
(read more: PhysOrg) (images: MPE)
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More information: The new work will be published in “The missing link: a low mass X-ray binary in M31 seen as an ultraluminous X-ray source”, Middleton, M. J. et al, Monthly Notices of the Royal Astronomical Society, in press.
A preprint can be downloaded from: http://adsabs.harvard.edu/abs/2011arXiv1111.1188M
