#90

The Tiniest Galaxy in the Universe

Meet Segue 2, the galaxy that is millions of times smaller than the Milky Way.

By Liz Kruesi|Tuesday, January 28, 2014
RELATED TAGS: COSMOLOGY
tiniest-galaxy
tiniest-galaxy

Segue 2, the smallest known galaxy, is just one of many similar diminutive galaxies astronomers expect to find around the Milky Way, as shown in this colorful simulation.

Garrison-Kimmel, Bullock/University of California, Irvine.

Astronomers can measure a galaxy’s mass by how stars move within it: The faster they move, the more massive it is. 

With this knowledge, a University of California, Irvine, team found that Segue 2, discovered in 2009, weighs at most 150,000 times more than our sun — the puniest galaxy known. (Our normal-size Milky Way is 10 million times more massive.) 

Segue 2 is probably just one of many such astronomical miniatures orbiting the Milky Way, says UCI astronomer Evan Kirby: “Simulations predict that there should be tens of thousands of these things.”

[This article originally appeared in print as "The Tiniest Galaxy in the Universe."]

Comment on this article
ADVERTISEMENT

Discover's Newsletter

Sign up to get the latest science news delivered weekly right to your inbox!

ADVERTISEMENT
ADVERTISEMENT
Collapse bottom bar
DSCMayCover
+

Log in to your account

X
Email address:
Password:
Remember me
Forgot your password?
No problem. Click here to have it emailed to you.

Not registered yet?

Register now for FREE. It takes only a few seconds to complete. Register now »