Friday, January 14, 2011
A Voorwerp. Not a Frog
Back in 2007, a Dutch school teacher discovered a very odd celestial object: It looked like a great, green blob floating in space and at the time it was inexplicable. This teacher was part of a vast amateur astronomy group of 250,000 smart people assisting in something called the Galaxy Zoo. These people took images of galaxies from Hubble and classified them into groups: spiral, elliptical, irregular, barred, etc.
The teacher, Hanny van Arkel, found something that was, at the time, inexplicable, although it looked a lot like a space frog. Given the name, "Hanny's Voorwerp," now "Hanny's Object," which I personally do not like as much, the frog is now considered to be a "twisting rope of gas, or tidal tail, about 300,000 light-years long that wraps around [a] galaxy."
In a press release from the University of Alabama, Dr. Bill Keel, professor of astronomy and leader of Hubble's Hanny's Voorep study (just how much would you like to have THAT on your resume?), presented two surprising findings:
"First, that very young stars are forming inside the tidal tail. "The region may have been churning out stars for several million years," said Keel. "They are so dim that they have previously been lost in the brilliant light of the surrounding gas."
Keel told us that this is remarkable because this is not the kind of environment in which you would usually find star formation.
Second, Hanny's Voorwerp was lit up by a powerful beacon of light called a quasar, which formed as a byproduct of the harsh conditions created by a supermassive black hole at the center of the galaxy. Keel said the tail likely formed as the result of energy from two merging galaxies. That green light we see is glowing oxygen.