ROAST ::

September 8-10. And after more than two weeks, at last some clear skies.

On 21 August I imaged C 30, aka the Deer Lick Group. In early September a supernova was discovered in this galaxy, so I decided to have a go at imaging it. Here’s an animation of the two images with the supernova marked:

So, a success. The 8 September session was interrupted by clouds so was limited to 90 minutes total exposure (the earlier one was 3 hours), so some of the fainter stars haven’t shown up well.

This supernova is designated SN 2026aaiv; more info and pictures here. It’s a type 1a supernova, which means it’s a binary system in which one of the stars (the one that exploded) is a white dwarf. A similar supernova was seen in this galaxy in 2025.

The clear(ish) skies meant I could at last have a go at doing a mosaic of the Andromeda Galaxy to get more of it in the frame. This is a megastack of a pair of 2-frame mosaics taken on 8 and 9 September; the occasional cloud on 8 September caused the left edge problem. It’s a large image, so click for biggie:

And for comparison, an unsharp-masked one (10,100,1). Not sure which is better:

Details:
Target: M 31 (Andromeda Galaxy)
Megastack session 1:
 Equipment: Dwarf Mini, Astro filter, perfect EQ
 Format: Two-frame mosaic, 1.0×1.8
 Time: 2026-09-08, 23:20 - 04:03
 Integration: 3hrs 42mins (222×60secs, +28 failures), gain 50
 Conditions: Clear with sporadic cloud; Bortle 6
Megastack session 2:
 Equipment: Dwarf Mini, Astro filter, perfect EQ
 Format: Two-frame mosaic, 1.0×1.8
 Time: 2026-09-10, 00:10 - 03:01
 Integration: 2hrs 30mins (150×60secs, +1 failure), gain 50
 Conditions: Clear; Bortle 6
Total integration: 6hrs 12mins
Processing: PhotoDesk equalisation, gamma

And so to bed…