Arp227
Galaxy in Pisces
About
NGC 474 is a lenticular galaxy of Pisces, roughly 250,000 light-years across and about 100 million light-years away. Faint tidal shells surround it, possibly left by a collision with another galaxy; the spiral NGC 470 lies about 8′ west. Arp listed the pair under "Galaxies with concentric rings".
Imaging tips
- Sources give about 7′ for NGC 474, with a very dim outer ring about 8′ across; NGC 470 is a smaller 2.8′ spiral.
- Only the bright bulge stands out in a 6 × 6 minute stack from a 25 cm scope; the shells need deep data. One imager gathered 42.1 hours with twin 152 mm refractors, 54 luminance frames of 1800 s.
- A 20′ field took in both galaxies in a 12 h 20 min LRGB stack, so a wider field than NGC 474 alone suits the pair.
- Faint at 22.6 mag/arcsec², so plan broadband data over many nights.
- Best around September and October; it stays below 44° from 50°N.
Facts
- Size
- 3′ × 2′
- Magnitude
- 12.0
- Coordinates
- RA 1h 20.1m, Dec +3° 25′
- Framing, APS-C
- longer than 4000 mm
- Framing, full frame
- longer than 4000 mm
- Best months
- Sep, Oct
- Peak altitude
- 43° from 50°N, 58° from 35°N