These are the pictures so far from 2017 and yes as the title says, it includes not only a comet but a supernova as well. And not just any old supernova either, this one's in another galaxy!
But first we will start off with this galaxy image.
This is the galaxy M106 (also known as NGC 4258). M106 is an intermediate spiral galaxy and is located in the Canes Venatici onstellation.
This galaxy was surprisingly easy to photograph from the city. Normally face-on or nearly face-on galaxies are quite dim compared to the local light pollution. However M106 seems to be quite bright even though its apparent magnitude is only listed as 9.1. It also frames well in the MN190 telescope and the reddish coloration works well with the spectral response of the sensor in the STF-8300M camera.
Besides having a well defined core, this galaxy also has a fairly large halo surrounding it. The halo does not show up that well in this image. But it is still faintly visible and I think that if I were to photograph it from a proper dark site it could be more prominent.
Just above M106 and a bit to the left is another galaxy, NGC 4248. And for those with a keen eye, above NGC 4248 are two more galaxies NGC 4231 (left) and NGC 4232 (right) near the top edge of the image. Besides these three, there are a few more small faint galaxies in this image as well.
Comet Johnson (C/2015 V2)
This is the first comet image I have ever taken and am pretty happy with the result. Its not perfect though.
The core looks oblong and has a dark band in it. Most likely this is a trailing effect that occurred because of the long (2hr+) exposure.
The trailing occurred because the telescope was set to track the background stars and the comet moved a bit relative to the stars during the exposure period.
So, the core of the comet became elongated as compared to surrounding stars.
Experienced comet imagers typically track the comet itself and let the stars trail instead. This would result in a more normal looking round comet core.
But like I said, this is my first comet and I used deep sky imaging techniques. So the stars came out quite nice but the comet trailed instead. Oh well, as a first try on a comet it still looks pretty good though.
Supernova SN 2017eaw
In May of 2017 I took delivery of a new mount, a 10Micron HPS GM1000. This is a very nice mount indeed and I wanted it for mobile, high precision imaging. Once I received the mount, I needed to do testing and learning.
Now, at the time I did this, it just so happened that the galaxy NGC 6946 and the cluster NGC 6939 were in a good position. So, I used them as a test target. Not a bad choice since I had stars, a cluster and a galaxy all in the same field. Little did I know that three days later a supernova would go off in that galaxy.
So the supernova did in fact occur in the galaxy on or about May 14, 2017. And I had a photo of it from a mere three days before. So, after learning about the supernova event, I followed up some days later and took another image after the fact.
These three images show the before, after and located supernova:
About 3 days before the supernova
About 14 days after the supernova
And this image indicates which "star" is the supernova.
Indeed, not really that spectacular from here. If anything, in this picture it looks a lot like any other star in the image. A simple white dot.
But consider that this particular dot is in another galaxy. Which means it is really, and I mean really, really super far away.
And as we can see in the image, from here all the other stars in that galaxy are far to dim to stand out at all. They just blend together to give the galaxy a very faint glow.
Yet from here on Earth, the supernova looks as bright as any star in our own galaxy. So from close up it must be… oh wow!
And so what is a supernova anyway you might ask? Well, it’s a star that has reached the end of its life, which caused it to collapse on itself then explode. Only a small fraction of stars are large enough to go supernova, our sun is not one of them.
Lastly, you might also ask, why exactly is this galaxy called the Fireworks Galaxy anyway? Well, it has a record number of observed supernovae in it and as we can see, they go off like fireworks.
And this brings us to the last image of the season. This is the Crescent Nebula, a famous emission nebula in the constellation Cygnus. It's located near the star Sadr and is in one of my favorite areas of the sky to view visually.
The nebula is quite faint and I've never actually seen it from my back yard in the city. But the brighter portion is apparently visible from a dark site and when seen in a large telescope it forms a crescent shape, hence the name.
The nebula mostly glows in the H-alpha wavelengths but I've seen images that reveal other wavelengths as well. The billowing red clouds surrounding the nebula are hydrogen clouds that also emit Ha light.
And thats it so far for 2017. The new mount is working great, the scopes all do their stuff and the sky is outstanding as always. Stay tuned for more once the fall and winter images start rolling in.