Tag Archives: gliese 581

Discovery Triples Number of Stars in the Universe

Astronomers detected the faint signature of small, dim red dwarf stars in nearby galaxies (right), and found they are much more numerous than in our own Milky Way (left). Image credit: Patrick Lynch/Yale University

Astronomers have discovered that small, dim stars known as red dwarfs are much more prolific than previously thought — so much so that the total number of stars in the universe is likely three times bigger than previously believed.

Because red dwarfs are relatively small and dim compared to stars like our Sun, astronomers hadn’t been able to detect them in galaxies other than our own Milky Way and its nearest neighbors before now. Therefore, they did not know how much of the total stellar population of the universe is made up of red dwarfs.

Now astronomers have used powerful instruments on the Keck Observatory in Hawaii to detect the faint signature of red dwarfs in eight massive, relatively nearby galaxies called elliptical galaxies, which are located between about 50 million and 300 million light years away. They discovered that the red dwarfs, which are only between 10% and 20% as massive as the Sun, were much more bountiful than expected. (more…)

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Potentially Habitable Planet Discovered

Washington, D.C. Astronomers have found a new, potentially habitable Earth-sized planet. It is one of two new planets discovered around the star Gliese 581, some 20 light years away. The planet, Gliese 581g, is located in a “habitable zone”—a distance from the star where the planet receives just the right amount of stellar energy to maintain liquid water at or near the planet’s surface. The 11- year study, published in the Astrophysical Journal and posted online at arXiv.org, suggests that the fraction of stars in the Milky Way harboring potentially habitable planets could be greater than previously thought—as much as a few tens of percent.


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