Messier 31 – The Andromeda Galaxy

Two other galaxies of note are in this image. Messier 110 is the oblong object to the lower right. Messier 32 is the bright, fuzzy ball located on the apparent edge of Andromeda, directly left of Andromeda’s bright center. Both M110 and M32 orbit the much larger M31.

This was my biggest imaging project by far, surpassing even the Elephant’s Trunk nebula from last week.

The Andromeda Galaxy is a large object in the sky–about the width of six full moons. The camera on the Dwarf 3 is large enough to fit nearly the whole thing into its field of view in telephoto mode, but only if the galaxy is oriented diagonally with respect to the imaging sensor chip (which is rectangular). This would not be a problem with a typical astro-imaging rig because the camera can be rotated to optimize the field of view. The Dwarf 3’s camera, however, is fixed with respect to the rest of the telescope body. As a result, the outer edges of the galaxy are clipped, as demonstrated in this screenshot from Stellarium.

I wasn’t content with the clipped view of the galaxy, so I experimented with putting together a mosaic of overlapping images that would, in theory, capture the entire object.

I centered the scope on the Andromeda Galaxy the first night, and then on the second and third nights I took pictures off-center to capture the clipped edges. When combined, though, there was a significant amount of imaging noise on the edges of the galaxy, so I took two more sets on the fourth night using the scheduling feature in the Dwarf 3 app. The scheduler lets you select one or more targets and set the exposure and time range to shoot each target.

I then downloaded the image files from all four nights–3,373 in total–and stacked them using Mosaic Mode in Deep Sky Stacker. Mosaic Mode pieces together all of the overlapping individual exposures into a single image. The image below is a lightly processed version of the raw mosaic:

Still, it didn’t quite work out as I had expected, but it was good enough to produce the image at the top of this post. I may try again another time, but I’m ready to move on to another target. If nothing else, this project gave me the opportunity to experiment with taking and processing mosaic images and using the very handy scheduling feature.

Click on the link below to view the full-size version of this image:

Messier 31 – The Andromeda Galaxy

Addendum: I went back and reprocessed M31 using a few new-to-me techniques. I think I like this version a little more.