This is the Andromeda Galaxy M31, the most distant object that can be seen by the naked eye. It’s the Milky Way’s nearest neighbour at about 2.5 million light-years from Earth. And it’s about twice the size of the Milky Way at about 200,000 light-years across.
YouTube “short”
This “short” on YouTube shows the stages of processing, which was almost completely carried out in my astrophotography processing software, Hera.
The image was taken using a quad-band filter. This was a mistake—it’s not usual to use a filter like this on galaxies, but it doesn’t seem to have affected the final result too badly.
Image details
Frames
- 55× 150-s light frames (Gain 900) from 68 overall (best 80%)
- 2 h 70 min 30 s total integrated exposure time from 2 h 50 min overall (best 80%)
- Full use of calibration frames (darks, flats, dark flats)
Equipment
- Explore Scientific ED 102 mm Apo f/7 refractor
- Revelation Adjustable Field Flattener
- Sky-Watcher EQ6-R PRO SynScan GOTO equatorial mount
- Altair Hypercam 294C PRO colour fan-cooled camera
- Altair quad-band one-shot colour (OSC) 2″ filter
- Pegasus FocusCube v2
- Altair 60mm guide scope
- Altair GPCAM2 AR0130 mono guide camera
- Hystou Rugged Fanless Mini PC i5 7260U
Software
- SharpCap 4.0
- PHD2
- DeepSkyStacker
- Hera 0.3
- Photoshop
- “Local contrast enhancement” from Astronomy Actions Tools
- “Enhance dust lanes” from Annie’s Actions
- Topaz DeNoise AI for almost negligible sharpening
