M84

NGC 4374 · Galaxy in Virgo

Magnitude: 9.1
Size: 6.5′ × 5.6′
Effective surface brightness: 21.6 mag/arcsec²
Best months: Mar, Apr, May
Declination: +13°
Filter: None (broadband target)

A lenticular galaxy at the start of Markarian's Chain. The chain is a great wide-field mosaic project.

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 M84, 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	15%	33 min200 subs	52 min311 subs	2 h 12 min794 subs
ZWO Seestar S50 Pro10 s subs	8%	37 min222 subs	57 min342 subs	2 h 24 min864 subs
ZWO Seestar S3010 s subs	9%	37 min223 subs	56 min334 subs	2 h 16 min816 subs
ZWO Seestar S30 Pro10 s subs	5%	40 min238 subs	1 h363 subs	2 h 32 min913 subs
DwarfLab DWARF 315 s subs	7%	45 min179 subs	1 h 13 min292 subs	3 h 17 min790 subs
DwarfLab DWARF mini15 s subs	9%	33 min132 subs	51 min206 subs	2 h 12 min528 subs
DwarfLab Draco30 s subs	9%	27 min54 subs	42 min85 subs	1 h 49 min219 subs
DwarfLab DWARF II15 s subs	6%	2 h 21 min565 subs	3 h 12 min769 subs	6 h 56 min1,663 subs
Vaonis Vespera II10 s subs	8%	33 min200 subs	52 min311 subs	2 h 12 min794 subs
Vaonis Vespera Pro10 s subs	7%	1 h 20 min482 subs	1 h 59 min715 subs	4 h 48 min1,730 subs
Vaonis Vespera 310 s subs	7%	32 min190 subs	49 min296 subs	2 h 07 min760 subs
Vaonis Vespera Pro 210 s subs	7%	1 h 16 min456 subs	1 h 53 min679 subs	4 h 36 min1,654 subs
Unistellar eQuinox 24 s subs	19%	42 min632 subs	54 min805 subs	1 h 44 min1,557 subs
Unistellar Odyssey4 s subs	19%	3 h 41 min3,310 subs	4 h 22 min3,936 subs	7 h 25 min6,674 subs
Celestron Origin10 s subs	13%	8 min49 subs	13 min80 subs	36 min217 subs
Celestron Origin Mark II10 s subs	15%	10 min62 subs	18 min107 subs	51 min304 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.

M84

How long with each smart telescope

Imaging the galaxy

Per-telescope pages