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The April 2010 issue of Astronomy Now, the UK's best-selling astronomy magazine, is now on sale at all good newsagents.



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The five-minute white dwarf waltz
...Utilising the resolving power of the ten-metre Keck telescope in Hawaii, astronomers from the University of Warwick and Radboud University in the Netherlands have confirmed the existence of a double white dwarf system where the two stars orbit one another every 5.4 minutes...
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Gamma-ray glow steeped in mystery
...An omnipresent fog of high energy gamma-ray radiation that bathes the entire Universe is being produced mostly by a mysterious, unknown source, revealed scientists this week at a meeting of the American Astronomical Society’s High-Energy Astrophysics Division...
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Lava likely made river-like channel on Mars
...Dried-up river channels on Mars are some of the best evidence that water once flowed on the surface of the red planet, but new analysis of a channel once thought to have been carved by water shows that it was in fact formed from lava...
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Sky merger yields
sparkling dividends

DR EMILY BALDWIN
ASTRONOMY NOW
Posted: October 13, 2009


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The Hubble Space Telescope has captured an image of a striking galaxy, revealing the celestial oddity as the product of a high-speed galactic collision between two Milky Way-like galaxies.

NGC 2623 resides 250 million light years away in the constellation of Cancer. The data used for this colour composite were taken in 2007 by the Advanced Camera for Surveys (ACS) aboard Hubble. Image: NASA, ESA and A. Evans (Stony Brook University, New York & National Radio Astronomy Observatory, Charlottesville, USA).

The two galaxies, collectively known as NGC 2623 or Arp 243, are in the late stages of merging – their cores have amalgamated into one central nucleus. Two tidal tails rich with young stars stream out from the cores, a classic sign that a merger event has taken place and that material has been frantically exchanged between the two original galaxies.

NGC 2623's prominent lower tail is also richly populated with bright star clusters – one hundred of them have been found in these observations, some of which are brighter than the brightest clusters we see in our own local neighbourhood. Star clusters in this interacting pair likely formed as part of a loop of stretched material associated with the northern tail, or from debris falling back onto the nucleus.

Merger events may also result in the 'turning on' of an active galactic nucleus, where one of the supermassive black holes residing at the centres of the two original galaxies is stirred into action. Matter is drawn in toward the black hole and the energy released heats up the surrounding disc of material, lighting up the galaxy across a wide range of energies.

NGC 2623 is bright in the infrared and thus is a member of the very luminous infrared galaxies (LIRG) group. It has been extensively studied by the Great Observatories All-sky LIRG Survey (GOALS) project that combines data from space observatories such as Hubble, Spitzer, Chandra and the Galaxy Evolution Explorer (GALEX).

2010 Yearbook
Our latest 132-page Astronomy Now special edition is an extravaganza of astronomy for the year ahead, with a complete 30-page guide to observing the planets, moon, meteor showers, two solar eclipses, and the deep sky in 2010.
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Hubble Reborn
Hubble Reborn takes the reader on a journey through the Universe with spectacular full-colour pictures of galaxies, nebulae, planets and stars as seen through Hubble's eyes, along the way telling the dramatic story of the space telescope, including interviews with key scientists and astronauts.
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3D Universe
Witness the most awesome sights of the Universe as they were meant to be seen in this 100-page extravaganza of planets, galaxies and star-scapes, all in 3D!
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Infinity Rising
This special publication features the photography of British astro-imager Nik Szymanek and covers a range of photographic methods from basic to advanced. Beautiful pictures of the night sky can be obtained with a simple camera and tripod before tackling more difficult projects, such as guided astrophotography through the telescope and CCD imaging.
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Starry Night
Explore the Universe with these new versions of the award-winning Starry Night Software. Available now from the Astronomy Now Store.
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Exploring Mars
Astronomy Now is pleased to announce the publication of Exploring Mars. The very best images of Mars taken by orbiting spacecraft and NASA's Spirit and Opportunity rovers fill up the 98 glossy pages of this special edition!
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Mars rover poster
This new poster features some of the best pictures from NASA's amazing Mars Exploration Rovers Spirit and Opportunity.
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