NGC 2551 is alenticular galaxy in the constellationCamelopardalis. The galaxy lies about 120 millionlight years away from Earth, which means, given its apparent dimensions, that NGC 2551 is approximately 60,000 light years across.[1] It was discovered byWilhelm Tempel on August 9, 1882.[3]
NGC 2551 is categorised as a lenticular galaxy however the galaxy featuresspiral arms. The galaxy has two well defined narrow spiral arms and many arm fragments, with the spiral pattern being between agrand design galaxy and a multiple spiral arm pattern.[4] The galaxy is seen at an inclination of 50°.[5]
The galaxy has a disk of counter-rotating gas forming stars. It is possible the gas of the disk was accreted from a gas-rich satellite.[5] Thestar formation rate of galaxy based on theH-alpha is estimated to be 0.65M☉ per year.[6]Inultraviolet a ring is visible lying 15 to 30 arcseconds from the nucleus. Apart fromexcitation from star formation there is also excitation frompost-AGB stars and shocks in the northern inner part of the ring.[7] The galaxy also has ahydrogen disk which appears disturbed, probably due to interactions with other galaxies.[8]
Onesupernova has been observed in NGC 2551, SN 2003hr. It was found by T. Boles on 31 August 2003 lying 48" west and 20".4 south of the centre of the galaxy at an apparent magnitude of 16.8.[9] Its spectral analysis showed it was atype II supernova several months post maximum.[10]
NGC 2551 is the foremost member of the NGC 2551 group, which also includes galaxiesNGC 2550, UGC 4390, and UGC 4413.[11] The group is part of the same galaxy cloud withNGC 2633,NGC 2634, NGC 2634A, and IC 2389.[11][12] NGC 2551 forms a pair with LEDA 2755603, a diffuse companion galaxy lying 2 arcminutes away.[13] UGC 4390 lies 14.4 arcminutes away.[8]
^abTang, Ya-Wen; Kuo, Cheng-Yu; Lim, Jeremy; Ho, Paul T. P. (June 2008). "Prevalence of Tidal Interactions among Local Seyfert Galaxies: The Control Experiment".The Astrophysical Journal.679 (2):1094–1127.arXiv:0802.4265.Bibcode:2008ApJ...679.1094T.doi:10.1086/587045.
