NGC 772 | |
Epoch: | J2000 |
Type: | SA(s)b[1] |
Dist Ly: | NaNMpc |
Z: | 2472 ± 3 km/s |
Appmag V: | 11.1 |
Size V: | 7.2 × 4.3 |
Constellation Name: | Aries |
Names: | UGC 1466, PGC 7525, Arp 78 |
NGC 772 (also known as Arp 78 or the Fiddlehead Galaxy[2]) is an unbarred spiral galaxy approximately 106 million light-years away in the constellation Aries. It was discovered on 29 November 1785 by German-British astronomer William Herschel.[3]
At around 200,000 light years in diameter, NGC 772 is somewhat larger than the Milky Way Galaxy,[4] and is surrounded by several satellite galaxies – including the dwarf elliptical, NGC 770 – whose tidal forces on the larger galaxy have likely caused the emergence of a single elongated outer spiral arm that is much more developed and stronger than the others arms. Halton Arp includes NGC 772 in his Atlas of Peculiar Galaxies as Arp 78, where it is described as a "Spiral galaxy with a small high-surface brightness companion".
Three supernovae have been observed in NGC 772. SN 2003hl (Type II, mag. 16.5)[5] was discovered on 20 August 2003. SN 2003iq (Type II, mag. 16.4)[6] was discovered on 8 October 2003.[7] SN 2022qze (type IIP, mag. 19.9) was discovered on 8 August 2022.[8]
NGC 772 probably has a H II nucleus, but it may be a transitional object.[9]