Sh2-301
HII Region in Canis Major
About
A faint emission nebula in Canis Major, roughly round and about 9′ × 8′ across with some dark lanes. Sources disagree on its distance, giving anywhere from 13,000 to 19,000 light-years, which would make it around 50 light-years wide.
Imaging tips
- Small at about 9′ × 8′ across, so plan on a long focal length and a fine pixel scale rather than a wide lens.
- As an emission nebula it suits narrowband: one imager shot Hα, OIII and SII at 20 × 10 minutes each, 10 hours in all.
- One imager recorded it with 12 four-minute frames from a modified DSLR and a light-pollution filter, 48 minutes in total.
- Best in December and January, when it still only reaches about 21° altitude from 50°N.
Facts
- Size
- 12′
- Magnitude
- —
- Coordinates
- RA 7h 9.9m, Dec −18° 30′
- Framing, APS-C
- 2020–3370 mm
- Framing, full frame
- 3090–5160 mm
- Best months
- Jan, Dec
- Peak altitude
- 22° from 50°N, 37° from 35°N