Photograph by European Southern Observatory

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This spectacular image of the young open star cluster Messier 47 is dominated by a sprinkling of brilliant blue stars. In contrast, the foreground holds a few older red giant stars, not part of the M47 cluster.

Photograph by European Southern Observatory

New Image of Blue Diamond Cluster Is a Cosmic Showpiece

Sky-watchers can catch their own glimpse of Messier 47, a group of hot, blue baby stars.

Astronomers are getting an early holiday treat: a stunning new portrait of a well-known cluster of hot blue and red stellar jewels known as Messier 47.

The spectacular image of the sparkling cluster—visible also to sky-watchers—was taken using a wide-field camera attached to a 2.2-meter telescope at La Silla Observatory in Chile. Located some 1,600 light-years from Earth, M47 is home to only about 50 stars. That's a surprisingly low number for an open cluster, a kind of grouping that usually contains hundreds or thousands of stars of roughly the same age.

One look at the new image shows that this stellar nursery, which is about 12 light-years across, is dominated by massive blue stars. These hot giants are estimated to be less than 80 million years old, making them real babies. Our own sun is believed to be some five billion years old—a middle-aged yellow dwarf star.

While the blue, diamond-like stars are the real standouts in this cosmic showpiece, a smattering of orange, garnet-like gems in the foreground makes for amazing contrast. These bloated red giant stars, which are not part of M47, have burned most of their fuel and have much cooler surface temperatures—only around 3,000°C (5,432°F), compared with 20,000°C (36,032°F) or more for their much younger blue counterparts.

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This sky chart shows the constellation Puppis and surrounding bright stars in the southeastern skies this week.

See for Yourself

Messier 47 is located in the southern constellation Puppis, the poop deck of the mythical ship Argo.

Start your hunt by locating Procyon, the brightest star in the constellation Canis Minor, now visible in the low southeastern sky near your local midnight. Look to its lower right for the closest faint, naked-eye star Samhot, about 14 degrees away.

M47 sits about 5 degrees to the lower right of Samhot—equal to the width of your three middle fingers at arm's length.

Messier 47 is fairly easy to find with naked eyes under dark sky conditions; it looks like a faint hazy patch. But your hunt can be made easier, especially under light-polluted skies, by using your trusty binoculars.

Look closely through binoculars or a telescope and you get a cosmic two-for-one-deal with another neighboring open star cluster, Messier 46. You'll find this object a tad dimmer at magnitude 6 and less impressive, despite containing a lot more stars—some 500 in all. But that's because M46 is much farther away than M47, sitting at a whopping 5,000 light-years away.

Happy hunting!

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