Category: Astronomy

Last night at the River Ridge Observatory I tried for several objects with my 11″ SCT at f/6.3 but my results were mixed. The first object, the face on galaxy M51 was just too low. The second, the globular cluster M13 wasn’t but the results were just “meh”. The third object, the Bubble Nebula in Cassiopeia, turned out acceptable though not spectacular. I set this up for a 90 minute run with plans for another and took a nap but found that the winds picked up after midnight and that gave my scope “the jitters” and I wound up tossing a third of my 90 minute session. My last target, the Helix Nebula, suffered the same gusty wind problem except it was 100% of the images were ruined. So I got home at 4AM with one image that I will probably do over.

The Bubble Nebula (NGC 7635) is part of a larger emission nebula that you can see here. The bubble was created by a hot type O star inside it whose stellar winds are pushing it outward. The UV radiation from that same star is exciting the gas at the edges of the bubble, and perhaps more of the larger cloud, causing it to glow. You see that brightest star below and to the left of center in the bubble? That’s not it. It is the smaller star above and to the left of that star that is the star creating the bubble.

Here is an image of the center of the Milky Way taken Wednesday night while I was trying to see Perseids. I used my Canon 800D with an 85mm prime lens at f/2.5 and a light pollution filter. The image was made from 26 two minute images, stacked then processed in Photoshop. In the upper right, the brightest object is the Lagoon Nebula and to the right and above that is the Trifid Nebula. Below the center, inside the Milky Way, the bright star is Alnasl and it is the tip of the spout of the Teapot. Well above and to the left of Alnasl is Klaus Media. Well to the left but almost even vertically of Alnasl is Klaus Australis. These are the three brightest stars in the image and form the three stars of the spout of the Teapot.

If I say so myself, this is probably the best image of M31 (the Andromeda Galaxy) that I ever took. It’s made up from about 2 1/2 hours of one minute images using my 11″ SCT at f/1.9 with my ZWO ASI294MC Pro camera at a gain setting of 120. Full disclosure: I nuked two satellite galaxies in the processing of this image as they were not looking good. That’s okay since this is art not science.

M31 is possibly the farthest object visible to the unaided eye at 2.5 million light years away. I say possibly because another galaxy, M33 is slightly further away and can be glimpsed in very dark skies. But that is a story for another time, this is about M31.

M31 was first described in 964AD by a Persian astronomer who recognized its “fuzziness”. Until about 100 years ago, this was called the Andromeda Nebula. Then, in 1925, Edwin Hubble (of space telescope fame) used the then largest telescope in the world to identify and measure specific stars in the nebula and realized just how far away the object is. Until recently, M31 was thought to be as much as 50% larger than our own Milky Way galaxy. Recent measurements though have shown that the Milky Way is actually somewhat larger.