Massive galaxy discovered made almost entirely of dark matter

26 August 2016 Astronomy Now

An international team of astronomers has discovered a massive galaxy that consists of 99.99 percent dark matter. Even though it is relatively nearby, astronomers had missed the galaxy, named Dragonfly 44, for decades because it is very dim. The galaxy lies about 300 million light-years away in the constellation Coma.


Active asteroid spun so fast that it exploded

23 March 2015 Astronomy Now

Astronomers used the 10-metre Keck II telescope in Hawaii to examine a so-called active asteroid, P/2012 F5, that mimics a comet with a tail, but ejects dust like a shot without an obvious reason. The researchers found that it had a very fast spin rate and probably fragmented.


Thermonuclear supernova ejects Galaxy’s fastest star

7 March 2015 Astronomy Now

Astronomers using the 10-metre Keck II and Pan-STARRS1 telescopes on Hawaii have discovered a Milky Way star travelling at a record 2.7 million miles per hour. Propelled by the thermonuclear detonation of a massive white dwarf companion, this hypervelocity star will escape the gravity of our Galaxy.