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Methane, but no new moons

New color images of Pluto show two different faces on the mysterious planet as New Horizons discovers no new moons or rings in its flight path

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Fitful reawakening

Black hole in Cygnus wakes up after 26 years

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Experience a once-in-a-lifetime northern lights tour with Astronomy magazine and TravelQuest International

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Year of Pluto

Revelations of a distant world

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Big eater

M87 has swallowed an entire galaxy in the last billion years

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Hubble at 25

How the space telescope changed the cosmos

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Two for one

Simulation suggests black holes may make ideal dark matter labs

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Indonesian Islands Eclipse

Explore Bali and witness a total solar eclipse in March 2016 with Astronomy magazine and TravelQuest International

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Venus volcanism

Evidence of hot lava flows discovered on Venus

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Uwingu Mars

Name a crater ... make an impact!

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Exclusive podcast series

Editor David J. Eicher conducts extensive interviews with the world's top astrophysicists, planetary scientists, and cosmologists

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Stellar beginnings

Best observational evidence of the universe's first-generation stars

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Methane, but no new moons

New color images of Pluto show two different faces on the mysterious planet as New Horizons discovers no new moons or rings in its flight path

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PICTURE OF THE DAYsee all »

NGC 6791

NGC 6791 is one of the most studied open clusters in the sky. This object lies in the constellation Lyra the Harp and has a mass of about 5,000 times that of our Sun. It is an old cluster, at about 8 billion years, but it contains some unusual younger stars (4 and 6 billion years old). It is also metal-rich (“metals” in astronomy refer to elements other than hydrogen and helium); old open clusters are usually metal-poor. It covers an area about half the width of the Full Moon. Look around the cluster, and you’ll spot a few galaxies that lie far in the background. (10-inch Astro Systeme Austria astrograph at f/6.8, SBIG STL-11000M CCD camera, RGB image with exposures of 110, 110, and 90 minutes, respectively)
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