My
First Supernova and a Comet
Just
to be clear, I DID NOT find the supernova; it is,
however, the first one I have imaged. Since I plan to spend a lot of
time on it, let's start with the comet.
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| Comet C/2015 V2 Johnson |
This
is Comet C/2015 V2 Johnson. You might notice that it looks like a big
fuzzy glowing ball. Well, that's right; that's the way comets look,
for the most part. For some reason, possibly imaging too early in the
night, it was difficult to image the tail. It may also have to do
with the movement of the comet. Or maybe the tail is just very diffuse and
hard to make out. This is a stack of just 2 images, each 3 minutes
long. But, if you look very closely, it appears the nucleus (head) of
the comet is slightly elongated, whereas the stars are not. That
implies movement of the comet during the 6 minutes total time of the
exposure. If you try hard, you can see the beginnings of the tail,
going down and to the left (about a 45 degree angle) from the
nucleus. However, when processing the image, the glow from the tail
quickly faded into the background glow from the sky; so, it doesn't
show up well here. I may try again, but using a more difficult
technique; that being to try to track the comet and not the stars.
That will be a real challenge for my mount.
On
the night of May 13th,
Utah
amateur Patrick Wiggins discovered a possible bright supernova in the
spiral galaxy NGC6946 in Cygnus. If confirmed, it will become the
10th supernova found in this explosion-rich galaxy in the past
century. The nickname for this galaxy is the Fireworks Galaxy, so it
appears to be living up to that name.
To
have some fun with this, I'm going to use some of my images to show
the supernova and give some idea of the degree of difficulty in
finding one, other than the aspect of just being lucky to have the
scope on the right galaxy on the right night.
Let's
start with an image of NGC6946 I took on the night of October 10,
2015
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| NGC6946 in Cygnus |
I
referred to it as a spider on this blog at the time. At least that's
what I thought it looked like. (Kinda still do, for that matter.)
There are a couple of things to note, here; 1) there are a lot of
stars in this image, and 2) even though there is some mottling of the
galaxy (mostly from the dust lanes), it is mostly just a glow with no
individual stars visible from
the galaxy.
What does that say about the stars visible? They are called
foreground stars, meaning they are between us and the galaxy NGC6946,
and are actually in our own galaxy, the Milky Way galaxy. They are in
no way associated with NGC6946.
So,
where was the supernova found? See below, which is a “marked up”
version of the above image, with the arrow showing where supernova
is.
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| Same image as above, but in black and white, showing where supernova will be found |
Well,
now for the money picture, the one we've all been waiting for. Mind
you, this is a black and white only image.
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| NGC6946 with supernova taken May 14, 2017 |
Having
trouble seeing it? This next image has a arrow pointing directly to
it.
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| Oh, THERE it is! |
Run back up to the first image of the galaxy and you'll see the "star" isn't there!
Finally,
I thought it might be fun to see how it's brightness compares to that
of the galaxy. Below is the above image, but with the foreground
stars (mostly) digitally removed. The supernova is at least as bright
as the nucleus of NGC6946, wouldn't you say? It's possibly as bright
as the entire galaxy. But that's just the way it is with supernovas.
 |
| Same image as above but without those pesky foreground stars |
It's
a lot easier to spot on this image, ya think? And while you've got
the brain working, remember that this thing went off at least 10
million years ago. We're just now finding out about it!
