H-NGC3184
Galaxy in Ursa Major
About
Ursa Major's Little Pinwheel is a spiral galaxy tipped close to face-on, about 40 million light-years distant, and takes its name from M101's look-alike spiral pattern. Six supernovae and similar outbursts have been recorded in it. William Herschel found it in 1787, and it is in the Herschel 400 list.
Imaging tips
- At about 7×7′ it fills a third to half of an APS-C frame at 3460–5770 mm, so a long focal length is required.
- Faint at 22.7 mag/arcsec², so plan for many hours of broadband data.
- One imager used 8 h 30 min at 1070 mm (36 × 10 min luminance, 5 × 10 min per colour) and described the galaxy as small for that focal length.
- Best around February and March; it peaks near 81° altitude from 50°N.
Facts
- Size
- 7′ × 7′
- Magnitude
- 9.8
- Coordinates
- RA 10h 17.9m, Dec +41° 25′
- Framing, APS-C
- 3460–5770 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Feb, Mar
- Peak altitude
- 81° from 50°N, 84° from 35°N