M32

NGC 221 · Galaxy in Andromeda

Magnitude: 8.1
Size: 8′ × 6′
Effective surface brightness: 20.9 mag/arcsec²
Best months: Sep, Oct, Nov
Declination: +41°
Filter: None (broadband target)

The compact elliptical companion of Andromeda, sitting on its disc. Appears in every M31 frame.

Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.

How long with each smart telescope

Total integration for a solid image of the M32, default sub length, recommended filter, and how much of each frame it fills. Click a cell for the full Bortle 1 to 9 table.
Telescope	In frame	Bortle 3 (rural)	Bortle 5 (suburban)	Bortle 7 (urban edge)
ZWO Seestar S5010 s subs	19%	10 min60 subs	14 min85 subs	33 min196 subs
ZWO Seestar S50 Pro10 s subs	10%	11 min66 subs	15 min93 subs	35 min213 subs
ZWO Seestar S3010 s subs	11%	11 min65 subs	15 min90 subs	33 min201 subs
ZWO Seestar S30 Pro10 s subs	6%	12 min70 subs	16 min99 subs	37 min225 subs
DwarfLab DWARF 315 s subs	8%	14 min55 subs	20 min81 subs	49 min196 subs
DwarfLab DWARF mini15 s subs	11%	10 min40 subs	14 min57 subs	33 min131 subs
DwarfLab Draco30 s subs	11%	15 min30 subs	15 min30 subs	27 min54 subs
DwarfLab DWARF II15 s subs	7%	39 min155 subs	50 min202 subs	1 h 42 min407 subs
Vaonis Vespera II10 s subs	9%	10 min60 subs	14 min85 subs	33 min196 subs
Vaonis Vespera Pro10 s subs	8%	23 min139 subs	32 min193 subs	1 h 11 min426 subs
Vaonis Vespera 310 s subs	9%	9 min57 subs	13 min81 subs	31 min188 subs
Vaonis Vespera Pro 210 s subs	8%	22 min132 subs	31 min184 subs	1 h 08 min407 subs
Unistellar eQuinox 24 s subs	23%	11 min167 subs	14 min206 subs	25 min379 subs
Unistellar Odyssey4 s subs	24%	56 min837 subs	1 h 05 min981 subs	1 h 47 min1,609 subs
Celestron Origin10 s subs	16%	5 min30 subs	5 min30 subs	9 min54 subs
Celestron Origin Mark II10 s subs	18%	5 min30 subs	5 min30 subs	13 min76 subs

Open in the calculator

Imaging the galaxy

Galaxies are broadband targets: their light is mostly starlight spread across the spectrum, so a dual-band filter throws most of it away and makes things slower, not faster. Shoot without a filter (or with a plain UV/IR cut) and rely on total time and a dark sky. The core of a galaxy is usually many times brighter than its outer disc, so a short stack shows the nucleus long before the arms; the figures here are for the arms and disc, not the core.

Field rotation in Alt-Az mode crops the edges of the stack over a long session, so on a big galaxy re-centre now and then or use EQ mode where your scope supports it.

M32

How long with each smart telescope

Imaging the galaxy

Per-telescope pages