Yesterday, I talked briefly about what infrared images can tell us about dust in spiral galaxies. In a funny coincidence, the European Southern Observatory put out a press release todayabout a new image that discusses a similar topic! In this case, though, the arms lead down to a bottomless pit: a black hole in the center of a spiral galaxy called NGC 1097. Galaxies are vast collections of stars, gas, and dust. At first glance, NGC 1097 looks like a fairly typical spiral galaxy:
Pretty, isn't it? Our Milky Way would look a lot like that from a few million light years away, too. Sometimes, this kind of galaxy is called a "grand design" spiral, because the spiral pattern is so big and obvious. But what's interesting is what happens when you zoom in on the nucleus:
The blobby ring there is a circle of dense clouds of gas and ...
