PGC 8961 (top) and 8970 (bottom) form an interacting pair of spiral galaxies, also known as Arp 273. Both galaxies are considerable distorted by their interaction, but PGC 8961’s arms and brilliant clouds of hot, bright young stars caused by the interaction are more obvious because it is nearly face-on to our line of sight; while PGC 8970’s form is more edge-on, and appears more distorted than its companion. (in some ways this is similar to M81 and distorted M82, a more widely separated galaxy pair far closer to our Milky Way galaxy.) Based on a recessional velocity of 7565 km/sec, PGC 8961 is about 350 million light years away. Given that and its apparent size of 1.9 by 1.0 arc-min, it is about 185 thousand light years across. This makes it more about twice the diameter and about eight times the volume (and most likely, mass) of our Milky Way galaxy.
- Right Ascension: 02h 22m 50s, Declination: +39d 27m 13 sec (current)
- Constellation: Andromeda
- Distance: 350 Mly (PGC 8970)
- Apparent magnitude: PGC 8961 mag 13.4, PGC 8970 mag 15.2
- Apparent size: PGC 8961 1.9 x 1.0 a-min, PGC 8970 1.2 x 0.3 a-min
- Exposure Dates: Oct thru Dec 2020
- Exposure: Lum: 17x1000s=4.72h, Red: 21x1000=5.83h, Green: 23x1000=6.39h, Blue: 20x1000=5.56h (total: 22.4 hrs)
- Instrument: RCOS 20 inch at f8.2 (fl=4116mm), SBIG ST8-XME (1pixel=0.4509 arc-sec)
- Processing: PixInsight