Mystery of the green blob revealed

One of the objects discovered through the Galaxy Zoo volunteer project, an effort to take advantage of the fact that us humans are far superior pattern-matching machines than modern computers, was a mysterious green blob dubbed "Hanny's Voorwerp". It's a huge irregular cosmic structure nearly the size of a small galaxy, and yet it is suspiciously devoid of stars.

Using radio telescopes, astronomers at ASTRON think they now have a good idea of what it is. They observed an energetic particle stream emanating from the center of a nearby galaxy IC 2497, generated by its supermassive black hole, which slams into the gas comprising Hanny's Voorwerp to make it glow. As for where all the gas comes from? It's probably the gas that was stripped from IC 2497 or another galaxy during a close encounter.

Radio jet (white contours) emanating from the centre of the nearby galaxy IC 2497 headed straight in the direction of Hanny's Voorwerp (green)
Radio jet (white contours) emanating from the centre of the nearby galaxy IC 2497 headed straight in the direction of Hanny's Voorwerp (green)

Eight days of astronomy podcasting

Do you love talking about astronomy? Do you love the sound of your own voice? Then consider volunteering ten minutes of your voice for some January episodes in the 365 Days of Astronomy podcast. This is a podcast that broadcasts a listener-produced episode for every day of 2009, but it needs more courageous contributors for shows early in the year. Particularly, they have eight days that still need to be filled in for January.

If I loved my voice and had the slightest bit of courage, I might be tempted to volunteer myself. But I'm not, so maybe February ...