It’s been a while since I posted a devastating spiral galaxy picture, so why not now? I present NGC 1187, a gorgeous barred spiral about 60 million light years away:
[Click to galactinate, or grab the 3300 x 1900 pixel version.]
This image was taken with the Very Large Telescope to help astronomers study a star called Supernova 2007Y that exploded in this galaxy. Can you find it? Yeah, good luck with that; there are a gazillion stars in the picture. The folks at the European Southern Observatory helpfully circled it in this annotated version. Were you right?*
Anyway, this was the second supernova in NGC 1187 in recent times; it also hosted one in 1982 (which had faded into obscurity by the time the above image was taken). Most spirals have supernovae in them every century or three, so this was unusual but not necessarily weird. The rate is statistical so you might get two close together, or a long stretch without one. The last one in our Milky Way was about 170 years ago, and the last known before that was 400 years ago.
NGC 1187 is a gas-rich galaxy, and is forming lots of stars. That might lead to a higher-than-normal supernova rate, since that means more high-mass stars are being born, only to explode a few million years later. Both of the recent supernovae in NGC 1187 were of the same type – the core collapse of a high-mass star – so maybe this does play into it. I suppose time will tell. If we get an elevated rate over the next few decades, that’ll be interesting.
Astronomers will of course continue to study this galaxy and look for more supernovae. The science of that would be well worth the time, and in the meantime we would get even more lovely pictures of this spectacular island universe.
Image credit: ESO