The fading comet

Cassiopeia and the comet and the galaxy
Cassiopeia and the comet and the galaxy

It was supposed to be a good chance of aurora last night so I stayed up late, which in my case is midnight. With no sign on increased activity I had to go to bed, just couldn’t keep my eyes open any more. But even if I missed the aurora (or not, because looking at last night’s aurora plot it never got really hot), I shot a few frames of Cassiopeia and the Pan-STARRS comet. The comet is now getting quite close to Cassiopeia so if I get a clear night next week, I’ll try to zoom in for a “close-up” of Cassiopeia and the comet. But as it is now, I used a wider angle so I can include the horizon as well. The comet is just barely visible in this small web version, and I can see it only because I know where it is.

Full resolution crops
Full resolution crops

I have also included full resolution crops of the details, so you get an idea of what I’m talking about. The weakest star you can see with normal eyesight is about magnitude +4 or +5. Think about the Pleiades – it is considered good vision if you can count seven stars in the cluster (provided you don’t have any light pollution), and the weakest of those seven is +4.76 (the higher the number, the weaker the star). The comet currently has a magnitude of around +5 but it is a bit fuzzy, not a distinctive dot like the stars. Absolutely impossible for me to see with naked eye, and I have trouble spotting it even with binoculars. It’s a little bit like night vision… you see things with better in the periphery of your vision, rather than looking straight at it. Same thing with the Andromeda galaxy, it should be visible at +3.44 but I can’t see it. And in the 100% crops you can see what I mean, both the galaxy and the comet are weak and fuzzy while the stars are clear.

Locating the comet
Locating the comet

The focal length I used for this was 45mm. In order to compensate for the shorter exposure time necessitated by the long-ish focal length, I used ISO 3200. Obviously, it gives me a lot of noise so I applied a 70% noise reduction in Lightroom and the result is not half bad. If I spent some on fine tuning the NR settings I could probably improve it but it’s good enough as it is… I mean, it’s not like I’m going to do poster size prints out of this!

For those of you interested in spotting the comet, I’ve marked it with a red dot in the last picture. I’ve also enhanced two stars in Cassiopeia because they are quite neatly pointing directly at the comet. The comet is moving up to the right, so in a few nights you will have to look down from the rightmost star in Cassiopeia to find it.

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