M13 is a globular cluster, consisting of about 300,000 stars, in the constellation Hercules. It’s about 25,100 light years away and 145 light years in diameter. Globular clusters are large collections of stars that are bound together by their gravity. In 1974 radio signals (the Arecibo Message) were beamed towards M31 in part as a message to potential other civilizations.
You can also see a small galaxy, NGC 6207, up and to the right of M13, although it’s estimated to be 30 million light years away.
I wasn’t really planning on imaging last night. We’re getting closer to the new moon again and so I decided to see if I’d finally got my autoguider working correctly. It was pretty windy into the evening, so I set up on the deck where the house would help block the wind. Once everything was aligned, connected and running I was really happy to see the auto-guiding working (as well as everything else).
The moon wasn’t going to be up for another hour so I decided to try and image something and M13 was relatively high above my trees in the western sky. I managed to get 25 exposures @ 180 seconds each before the moon started to brighten the sky too much. Once I was all done I realized I never focused my telescope, but I had locked it from the prior session and it was pretty close to focused. I’m sure I got a little blurring from the high winds causing all kinds of atmospheric distortion as well, but in the end I got a fairly good image. It might be interesting to try another night and see how much sharper of an image I can get.