Weird galaxy discovered at a distance of 9.4 billion light-years

A team led by Arjen van der Wel of the Max Planck Institute for Astronomy in Heidelberg, Germany has announced that it has made a “weird and interesting discovery,” more precisely described as the most distant gravitational lens ever seen. The lensing object is a galaxy some 9.4 billion light-years away—an enormous distance in a universe that burst into existence just 13.8 billion years ago.

The object being lensed—its image is split into four distinct spots of light—is obviously even more remote, although it’s so small and faint that it’s hard to assign its distance a hard number. What makes this discovery so weird, though, isn’t its distance but the nature of the thing being magnified. It’s a tiny dwarf galaxy whose weight in stars adds up to only about 100 million Suns’ worth—a piker compared with the Milky Way’s 100 billion or more. The overall color of the galaxy tells astronomers that it’s also very young—no more than 40 million years old—and forming stars at a furious rate.

Dwarf galaxies aren’t especially rare; astronomers keep finding them flitting around the Milky Way, and think many more are waiting to be found. But these tiny galaxies can’t sustain bursts of star formation for very long since they don’t have a lot of raw material to work with. That ought to have made this one very hard to spot, since it was at such a distance and it would have been bright enough to see only for a relatively small sliver of its lifespan.

That, plus the inherent difficulty involved in  the lensing effect occurring at all—the foreground and background objects have to line up with exquisite precision—makes the fact that this lensed galaxy ever turned up in telescopes even more improbable, the result of just the right conditions and angles converging at just the right time.

To read more about the discovery, click here.