M110

NGC 205 · Galaxy in Andromeda

Magnitude: 8.1
Size: 22′ × 11′
Effective surface brightness: 22.7 mag/arcsec²
Best months: Sep, Oct, Nov
Declination: +42°
Filter: None (broadband target)

Andromeda's larger, diffuse elliptical companion. Low surface brightness; it fades into the background in short stacks.

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 M110, 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	51%	1 h 23 min498 subs	2 h 20 min841 subs	6 h 31 min2,345 subs
ZWO Seestar S50 Pro10 s subs	27%	1 h 32 min555 subs	2 h 34 min927 subs	7 h 05 min2,553 subs
ZWO Seestar S3010 s subs	31%	1 h 35 min568 subs	2 h 32 min912 subs	6 h 43 min2,416 subs
ZWO Seestar S30 Pro10 s subs	16%	1 h 39 min596 subs	2 h 45 min988 subs	7 h 30 min2,698 subs
DwarfLab DWARF 315 s subs	22%	1 h 46 min426 subs	3 h 15 min780 subs	9 h 42 min2,328 subs
DwarfLab DWARF mini15 s subs	31%	1 h 22 min328 subs	2 h 19 min557 subs	6 h 30 min1,559 subs
DwarfLab Draco30 s subs	30%	1 h 06 min133 subs	1 h 54 min228 subs	5 h 23 min646 subs
DwarfLab DWARF II15 s subs	20%	6 h 21 min1,524 subs	9 h2,161 subs	21 h4,945 subs
Vaonis Vespera II10 s subs	26%	1 h 23 min498 subs	2 h 20 min841 subs	6 h 31 min2,345 subs
Vaonis Vespera Pro10 s subs	23%	3 h 26 min1,237 subs	5 h 27 min1,960 subs	14 h5,121 subs
Vaonis Vespera 310 s subs	25%	1 h 18 min470 subs	2 h 13 min801 subs	6 h 14 min2,245 subs
Vaonis Vespera Pro 210 s subs	22%	3 h 14 min1,166 subs	5 h 10 min1,860 subs	14 h4,895 subs
Unistellar eQuinox 24 s subs	64%	1 h 58 min1,772 subs	2 h 34 min2,308 subs	5 h 10 min4,651 subs
Unistellar Odyssey4 s subs	65%	11 h9,594 subs	13 h11,544 subs	22 h20,066 subs
Celestron Origin10 s subs	43%	19 min115 subs	35 min212 subs	1 h 46 min639 subs
Celestron Origin Mark II10 s subs	49%	23 min140 subs	47 min280 subs	2 h 29 min894 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.

M110

How long with each smart telescope

Imaging the galaxy

Per-telescope pages