Bode's Galaxy
M81, NGC 3031 · Galaxy in Ursa Major
- Magnitude
- 6.9
- Size
- 27′ × 14′
- Effective surface brightness
- 22.0 mag/arcsec²
- Best months
- Jan, Feb, Mar
- Declination
- +69°
- Filter
- None (broadband target)
A big, bright grand-design spiral that circles the pole for northern imagers, so it is available all year. Shares a frame with M82.
Reachable from mid-northern latitudes (UK, northern US, central Europe) and from the south.
How long with each smart telescope
| Telescope | Bortle 3 (rural) | Bortle 5 (suburban) | Bortle 7 (urban edge) |
|---|---|---|---|
| ZWO Seestar S5010 s subs | 34 min206 subs | 50 min298 subs | 1 h 57 min701 subs |
| ZWO Seestar S50 Pro10 s subs | 28 min169 subs | 45 min269 subs | 1 h 57 min704 subs |
| ZWO Seestar S3010 s subs | 25 min152 subs | 41 min244 subs | 1 h 48 min647 subs |
| ZWO Seestar S30 Pro10 s subs | 30 min182 subs | 48 min286 subs | 2 h 04 min744 subs |
| DwarfLab Dwarf 315 s subs | 41 min163 subs | 1 h 04 min258 subs | 2 h 48 min672 subs |
| DwarfLab Dwarf Mini15 s subs | 23 min92 subs | 38 min154 subs | 1 h 45 min422 subs |
| DwarfLab Dwarf II15 s subs | 1 h 51 min443 subs | 2 h 33 min614 subs | 5 h 39 min1,358 subs |
| Vaonis Vespera II10 s subs | 25 min152 subs | 41 min244 subs | 1 h 48 min647 subs |
| Vaonis Vespera Pro10 s subs | 1 h 13 min440 subs | 1 h 45 min633 subs | 4 h 06 min1,479 subs |
| Unistellar eQuinox 24 s subs | 34 min504 subs | 43 min648 subs | 1 h 25 min1,274 subs |
| Unistellar Odyssey4 s subs | 2 h 58 min2,675 subs | 3 h 33 min3,196 subs | 6 h 05 min5,476 subs |
| Celestron Origin10 s subs | 6 min36 subs | 10 min63 subs | 29 min177 subs |
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.
Per-telescope pages
- How long to image the Bode's Galaxy with the ZWO Seestar S50
- How long to image the Bode's Galaxy with the ZWO Seestar S50 Pro
- How long to image the Bode's Galaxy with the ZWO Seestar S30
- How long to image the Bode's Galaxy with the ZWO Seestar S30 Pro
- How long to image the Bode's Galaxy with the DwarfLab Dwarf 3
- How long to image the Bode's Galaxy with the DwarfLab Dwarf Mini
- How long to image the Bode's Galaxy with the DwarfLab Dwarf II
- How long to image the Bode's Galaxy with the Vaonis Vespera II
- How long to image the Bode's Galaxy with the Vaonis Vespera Pro
- How long to image the Bode's Galaxy with the Unistellar eQuinox 2
- How long to image the Bode's Galaxy with the Unistellar Odyssey
- How long to image the Bode's Galaxy with the Celestron Origin