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A Comprehensive Field Guide to the Ngc Volume 1: Autumn/Winter (Andromeda-Eridanus)

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A Comprehensive Field Guide to the Ngc Volume 1: Autumn/Winter (Andromeda-Eridanus) A COMPREHENSIVE FIELD GUIDE TO THE NGC VOLUME 1: AUTUMN/WINTER (ANDROMEDA-ERIDANUS) BHAVESH JIVAN-KALA PAREKH A COMPREHENSIVE FIELD GUIDE TO THE NGC VOLUME 2: AUTUMN/WINTER (FORNAX-VOLANS) BHAVESH JIVAN-KALA PAREKH A COMPREHENSIVE FIELD GUIDE TO THE NGC VOLUME 3: SPRING/SUMMER (ANTILA-INDUS) BHAVESH JIVAN-KALA PAREKH A COMPREHENSIVE FIELD GUIDE TO THE NGC VOLUME 4: SPRING/SUMMER (LEO-VULPECULA) BHAVESH JIVAN-KALA PAREKH Front Cover images: Vol 1: NGC 772/ARP 78 Vol 2: NGC 7317-18-19-20 Stephen’s Quintet Vol 3: NGC 4038-39/ARP 244 Antennae Galaxies Vol 4: NGC 5679/ARP 274 Galaxy Triplet Three of the galaxies in this famous grouping, Stephan's Quintet, A beautiful composite image of two colliding galaxies, the A system of three galaxies that appear to be partially overlapping in NGC 772, a spiral galaxy, has much in common with our home are distorted from their gravitational interactions with one another. Antennae galaxies, located about 62 million light-years from Earth. the image, although they may be at somewhat different distances. galaxy, the Milky Way. Each boasts a few satellite galaxies, small One member of the group, NGC 7320 (upper right) is actually The Antennae galaxies take their name from the long antenna-like The spiral shapes of two of these galaxies appear mostly intact. galaxies that closely orbit and are gravitationally bound to their seven times closer to Earth than the rest. "arms," seen in wide-angle views of the system. These features The third galaxy (to the far left) is more compact, but shows were produced by tidal forces generated in the collision, which parent galaxies. One of NGC 772’s spiral arms has been distorted CREDITS: NASA , ESA , and the Hubble SM4 ERO Team evidence of star formation. Two of the three galaxies are forming began more than 100 million years ago and is still occurring. and disrupted by one of these satellites (NGC 770 — not visible in new stars at a high rate. This is evident in the bright blue knots of The collision has triggered the formation of millions of stars in star formation that are strung along the arms of the galaxy on the the image here), leaving it elongated and asymmetrical. clouds of dust and gas in the galaxies. The most massive of these right and along the small galaxy on the left. young stars have already sped through their evolution in a few However, the two are also different in a few key ways. For one, NGC The largest component is located in the middle of the three. It million years and exploded as supernovas. appears as a spiral galaxy, which may be barred. The entire system 772 is both a peculiar and an unbarred spiral galaxy; respectively, Many of the fainter objects in the optical image are clusters resides at about 400 million light-years away from Earth in the this means that it is somewhat odd in size, shape or composition, containing thousands of stars. constellation Virgo. A pair of foreground stars inside our own Milky and that it lacks a central feature known as a bar, which we see in Way are at far right. This is a composite image from the Chandra X-ray Observatory many galaxies throughout the cosmos — including the Milky Way. (blue), the Hubble Space Telescope (gold and brown), and the CREDITS: NASA, ESA, M. Livio and the Hubble Heritage Team (STScI /AURA ) These bars are built of gas and stars, and are thought to funnel and Spitzer Space Telescope (red). transport material through the galactic core, possibly fueling and CREDITS: NASA , ESA , SAO, CXC, JPL-Caltech, and STScI ; igniting various processes such as star formation. Acknowledgment: J. DePasquale (Harvard-Smithsonian CfA), and B. Whitmore (STScI ) CREDITS: Image: ESA/Hubble & NASA, A. Seth et al. 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