Sombrero Galaxy

M104, NGC 4594 · Galaxy in Virgo

Magnitude: 8.0
Size: 9′ × 4′
Effective surface brightness: 21.5 mag/arcsec²
Best months: Mar, Apr, May
Declination: -12°
Filter: None (broadband target)

The bright bulge and knife-edge dust lane are obvious within an hour. Low from northern Europe, so catch it near the meridian.

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 Sombrero Galaxy, 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	21%	20 min122 subs	31 min186 subs	1 h 18 min467 subs
ZWO Seestar S50 Pro10 s subs	11%	22 min135 subs	34 min204 subs	1 h 25 min508 subs
ZWO Seestar S3010 s subs	13%	22 min135 subs	33 min199 subs	1 h 20 min480 subs
ZWO Seestar S30 Pro10 s subs	7%	24 min144 subs	36 min217 subs	1 h 29 min537 subs
DwarfLab DWARF 315 s subs	9%	27 min109 subs	44 min175 subs	1 h 56 min464 subs
DwarfLab DWARF mini15 s subs	13%	20 min80 subs	31 min123 subs	1 h 18 min311 subs
DwarfLab Draco30 s subs	12%	16 min33 subs	25 min51 subs	1 h 04 min129 subs
DwarfLab DWARF II15 s subs	8%	1 h 24 min338 subs	1 h 54 min457 subs	4 h 04 min977 subs
Vaonis Vespera II10 s subs	10%	20 min122 subs	31 min186 subs	1 h 18 min467 subs
Vaonis Vespera Pro10 s subs	9%	48 min291 subs	1 h 11 min426 subs	2 h 49 min1,017 subs
Vaonis Vespera 310 s subs	10%	19 min115 subs	29 min177 subs	1 h 14 min447 subs
Vaonis Vespera Pro 210 s subs	9%	46 min275 subs	1 h 07 min405 subs	2 h 42 min972 subs
Unistellar eQuinox 24 s subs	26%	25 min376 subs	32 min476 subs	1 h 01 min913 subs
Unistellar Odyssey4 s subs	27%	2 h 10 min1,953 subs	2 h 34 min2,317 subs	4 h 21 min3,909 subs
Celestron Origin10 s subs	18%	5 min30 subs	8 min48 subs	21 min128 subs
Celestron Origin Mark II10 s subs	20%	6 min38 subs	11 min64 subs	30 min179 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.

Sombrero Galaxy

How long with each smart telescope

Imaging the galaxy

Per-telescope pages