Early next month, astronomers from across the U.S. (and even further abroad) will converge on Austin, Texas for our annual winter meeting of the American Astronomical Society. Several thousand astronomers will be prowling the streets and crowding into the convention center, each presenting their own research.
I'm preparing a poster with some of my research to show off at the meeting. As my poster will be competing for attention with a few hundred other posters, I'm trying to whip up some flashy graphics to draw people in. It's a little sad that flashiness and not science is part of the draw, but that's the way things are.
Anyway, the picture above is a near-true color image of the center of the star cluster Messier 67 that I put together. The images were taken with the 6.5-meter MMT telescope south of Tucson, Arizona. Messier 67 itself is about 2800 light-years away in the constellation Cancer. The stars in the star cluster are about 4 billion years old, or just a little younger than our Solar System.
If you look at the large version of the image (click on the image above), you can see several types of stars. The brighter, orangish stars are red giants, stars that have exhausted their hydrogen fuel, and have swollen up from the size of our sun to a star larger than the Earth's orbit around the sun.
At the lower right, you can see a bright, bluish star. This star is known as a "blue straggler." Based on the star's color and brightness, it should be much younger than the star cluster. But we also know that it is part of the star cluster, and we know that all stars in a star cluster are the same age. So, this star is thought to be the result of two normal stars colliding and merging into a single star.
Meanwhile, most of the faint stars you see are stars like the sun, and some of these may even have planets around them (though, so far, we haven't found any). So, when I look at this cluster, it is possible that some alien astronomer is looking back at us.