Messier 37 - The Andromeda Galaxy
A barred spiral galaxy that rarely need an introduction. Our nearest galactic neighbour, so close that it was initially mistaken as a nebula within our own galaxy upon discovery. It lies 2.5 million ly from Earth in the constellation of Andromeda. It is the largest galaxy in our Local Group but still share approximately the same gravitationally bound mass as the Milky Way at around 1 trillion solar masses. Already in 1912 astronomers realized that the Andromeda galaxy was heading towards us. For a long time a violent collison was thought to be inevetable, causing massive amounts of star birth, supernovae and perhaps even toss our Sun into a different orbit. In fact it is approaching us at a calculated speed of 110km per second (indicated by blueshift) and the two galaxies are already in contact.
Galaxies are surrounded by huge amounts of gas creating a sort of halo. These halos can stretch incredibly far and studies show that Andromeda is reaching approximately halfway to the Milky Way, which then implies that the outer matter of our own galaxy is already reaching far enough for contact. Galaxy mergers are fairly common and both Andromeda and the Milky Way have merged with satelitte galaxies in the past. However new studies show that we may not be in for a galactic head on collision, even the timescale has shifted dramatically. It’s now beleived, based on computer simulations, that there is a 50-50 percent chance of a collision within the next 10 billion years. As opposed to less than ten years ago where it was thought to be a direct impact in less than 5 billion years - of which the new simulations only give a 2 percent chance of happening.

Watch this brilliant animation to see what our galaxy merger could look like!

Nova AT 2025abao
At the time I started imaging this object I was not aware of the nova, in fact my stack of images show very little indicating that there’s something going on at all. This, coincidentally, is because it was only discovered the same day as I started imaging it (17.10.25). At the time of discovery it had reached Mag 17.8. This is considered to likely be a luminous red nova which is a stellar explosion thought to be caused by two merging stars. They are not related to regular novae which are explosions that occur on the surface of white stars. However, as far as I can tell, they still need photometry data to properly assess this.

I’ve created two animations; Revision F and revision G. I was happy to see that my first night didn’t really show much other than a faint dot of light, this makes the before/after comparison much more impressive to watch. The animation is 3x drizzled and heavily cropped. Revision G is also upsampled approximately by 2-3x as well. Dates and amount of data per frame:

Frame 1 - 17/18.10.25: 597×30s (F/2)
Frame 2 - 30/31.10.25: 907×30s (F/2.8)
Frame 3 - 18/19.11.25: 1121×30s (F/2.8)
Frame 4 - 20/21.11.25: 457×30s (F/2.8)

The largest change in brightness is between frame 1 and 2, but there is also a minor jump in brightness from frame 2 to 3 as well. Frame 4 show a slight decrease I think, but it’s hard to tell if that’s just coincidentaal due to the amount of data or a real decrease. A collective amateur observation list can be found here, have a look!

Capture info
I chose Andromeda to be my second test of a budget-friendly astrophotography rig using relatively cheap, second hand gear and a planetary camera that otherwise only gets used for planetary imaging once in a while. My first image was comet C/2025 A6 Lemmon which turned out well - but this is the first long exposure DSO test for this setup. I’m fairly undersampled with the Samyang 135 which makes it ideal to drizzle. In return the resolution I get is pretty impressive. The fast f-ratio and light collecting capabilites forced me to use pretty fast shutter speeds as 30 seconds was on the border of saturating. At F/2 the galaxy and star cores were burnt out. Luckily handling a large amount of files isn’t such a big deal considering they are so small to begin with (less than 16MB). With ambient temperatures close to -10c sensor temp isn’t really an issue either. The sensor show a lot of noise in single expoures so dithering and calibration is key.

This is also the first attempt at Andromeda since I started out with a tracker and my old DSLR, first attempt here and here’s the second. I’ve always been meaning to image it again, but it’s always fallen down on my priority list due to needing a mosaic with my refractor, someday I’ll get there but for now this will do!
The ASI678 is not the cheapest planetary camera out there, but I feel confident that good results could be replicated with most of them if we are patient enough to gather the necessary data.

Other notable objects:
Messier 31 and its surroundings is littered with interesting objects. Red Supergiants, Blue Supergiants, dwarf galaxies, clusters and even nebulae large enough to be catalogued. It’s a true treasure trove of interesting objects in a distant galaxy actually close enough to explore in great detail with larger resolution telescopes. It would be impossible to give them all a proper mention, but i’ll make some worthy efforts to mention a few!

Messier 110
An eliptical dwarf galaxy that is a satellite of the Andromeda Galaxy.

Messier 32
Another dwarf galaxy and satelitte of M31. It’s a rare kind of compact elliptical class of galaxies with very dense concentration of stars. Half the stars are concentrated within the inner core which exlpain why it gets saturated so quickly. A series of very short exposures may reveal more structures but may require a bit more native resolution.

2MASS J003848781+4041056

BA 1-441 & BA 1-437
Two of many catalogued HII regions in the galaxy.

BA 1-452
An emission object that houses the Wolf-Rayet star LGGS J004005.65+405848.1.

BA 1-360, 1 -362 and 1-374
The right arrow points towards a mag 18.346 Blue Supergiant (PSO J009.9362+40.3489) and the emission object BA 1-362 above.
The middle one towards BA 1-362 which is an emission object that includes a mag 21.9 potential Red Supergiant (2MASS J00394291+4020510).
The left arrow points towards BA 1-374, another HII region that also includes a mag 19.115 Wolf-Rayet star (MAC OB 138-1)

NGC 206
A massive star forming region embedded in the Andromeda Galaxy.