European Association for Astronomy Education

Source: W.M. Keck Observatory

Segue 1 galaxy. We are not joking!
Image credit: Keck/Marla Geha

Astronomers using the 10-meter Keck II telescope in Hawaii have confirmed in a new paper that a troupe of about 1000 small, dim stars just outside the Milky Way comprise the darkest known galaxy, as well as something else: a treasure trove of ancient stars.

By “dark” astronomers are not referring to how much light the galaxy, called Segue 1, puts out, but the fact that the dwarf galaxy appears to have 3,400 times more mass than can be accounted for by its visible stars. In other words, Segue 1 is mostly an enormous cloud of dark matter decorated with a sprinkling of stars. (read more)

Source: ESA/Hubble Science Release heic1106

Image credit: NASA, ESA, J. Richard (CRAL) and J.-P. Kneib (LAM). Acknowledgement: Marc Postman (STScI)

Using the amplifying power of a cosmic gravitational lens, astronomers have discovered a distant galaxy whose stars  were born unexpectedly early in cosmic history. This result sheds new light on the formation of the first galaxies, as well as on the early evolution of the Universe. (read more)

Source:W.M. Keck Observatory News and Outreach

Artist's impression of an extrasolar planet.
Credit: ESO/L. Calçada.

Planet hunters using Keck Observatory have detected an extrasolar planet that is only four times the mass of Earth. The planet is the second smallest exoplanet ever discovered and adds to astronomers’ growing cadre of low mass planets called super-Earths. (read more)