Timing Is Everything

Usually when an astronomer, professional or amateur, takes a picture of a piece of sky through a telescope, they will compare it to older pictures of the same spot to see if there's something new hanging around. You check your image against the older ones, and if yours have something new, then astronomers have a new toy to play with. Often it's a supernova or another temporary phenomenon. Most of the time these comparisons are made with archives or records, perhaps online or perhaps at an observatory, and they may have to go back several years to see if the new image actually shows something new.

Or in the case of Argentine amateur astronomer Victor Buso, you can compare against your own shots taken about 45 minutes earlier and find a supernova that more or less just happened while you were watching. And to make it even cooler, these are the first images you've shot with your new camera that you were just testing out.

Buso took the pictures in September 2016 and major observatories immediately started studying the supernova, called SN 2016gkg. This made for the chance to observe its development more or less in real time, unlike any supernova "shock breakout" ever before studied.

Supernovae happen when really big stars use up all their hydrogen and start burning the leftover elements. Rather than the nice stable fusion process produced by hydrogen, other elements make for a much more unstable reaction that eventually leads to a really big explosion. How big? Well, the one Buso saw was in a galaxy 65 million light years away on a 16-inch telescope that he has in a home-built observing tower on his roof he calls Observatorio Busoniano. He spent less on the scope than most people spend on a used car. (You can see a picture of Buso and his scope here). So your eclipse glasses would probably not be enough to look at it if you were closer.

Type II supernovae are a little wonky. The interior core of the star collapses and then explodes so quickly that the star's outer layers are undisturbed, like a tablecloth being pulled from under the dishes so fast they stay in place. Those layers don't blast outward until the shock wave from the explosion hits them, and that's what the locksmith from Rosario, Argentina, captured with his new camera. Astronomers had not seen that process happen right in front of their lenses before, so they now have a wealth of new data to examine and theorize with.

In reality, of course, Buso did not see SN 2016gkg explode as he watched. Since it's far away -- 65 million light-years, remember -- the light from the event had been traveling 65 million years and finally reached the earth that September night. So it didn't happen in 2016 -- more like 64,997,984 BC, which is a long, long time ago.

Waitaminute. A gigantic explosion a long time ago in a galaxy far, far away? You don't suppose...