Arp148 — Mayall's Object
Galaxy in Ursa Major
About
Mayall's Object, two galaxies that collided about 450 million light-years away in Ursa Major. Arp listed it among galaxies with associated rings. It looks like a ring galaxy with a tail, and was first seen in 1940 as a question-mark-shaped nebula.
Imaging tips
- Only about 0.5′ across in one source, so it is too small to frame: use a long focal length and a fine pixel scale.
- Faint at 22.6 mag/arcsec² and a galaxy, so broadband data and a long total integration are the sensible route.
- One imager called its faint shape challenging to capture and used 8 frames of 6 minutes at 1600 mm with a light-pollution filter.
- Best around February and March; it passes about 81° altitude from 50°N.
Facts
- Size
- 1′ × 1′
- Magnitude
- 14.0
- Coordinates
- RA 11h 3.9m, Dec +40° 51′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Feb, Mar
- Peak altitude
- 81° from 50°N, 84° from 35°N