This week a quintet of galaxies takes center stage on Looking Up.
What would you say if I told you there was a beautiful quintet available to you, right now? Would you reach for your headphones? Well, in this case, it’s not a lovely musical interlude, but rather an amazing and beautiful grouping of galaxies high in the Colorado night sky, called Stephan’s Quintet.
First recorded by Edourad Stephan in 1877, this group of five galaxies is both beautiful to look at, and kind of freaky to understand. It seems four of the five galaxies are tightly bound to each other gravitationally. Indeed, there is evidence that before too many more billions of years pass, they will all collapse into one huge galaxy.
But that’s not the strangest part. In the 1970s, astronomers detected what seemed to be a strange and mysterious filament of something emitting radiation in the space between the galaxies. More advanced telescopes in recent years let us see that this filament is actually a massive, inter-galactic shock wave, like a sonic boom on Earth, heating the intergalactic gases to millions of degrees. This is likely due to one of the galaxies smacking into the gas between the other galaxies. And as shock waves go, this one is a biggie – it’s already bigger than our own Milky Way galaxy. So, if you are planning a trip to Stephan’s Quintet, be sure to try to catch a wave.
If you’d like to take a closer look at Stephan’s Quintet or any of the wonderful and amazing things in the sky, please visit csastro.org for a link to information on our monthly meetings and our free public star parties.