NGC 751 was discovered 66 years after the discovery of NGC 750. German-born British astronomer William Herschel was first to discover a galaxy at this location on September 12, 1784, but he did not resolve this close pair, therefore he described it as a single object NGC 750.[3][4]
NGC 751, which is smaller and fainter than NGC 750, was first resolved by Irish engineer and astronomer Bindon Stoney on October 11, 1850, who used Lord Rosse's 72" telescope.[3]
Interaction with NGC 750
At least 100,000,000 years have passed since the moment of the first strong tidal perturbation between these two galaxies.[5] Both galaxies are characterized by strong tidal interactions and distortions, and they are still in the process of efficient tidal interaction.[5]
The distance between the centers of this pair is 21", or 10 kpc in projection.[6][5] Both galaxies have almost identical central radial velocities.[5] While NGC 750 exhibits nearly flat radial velocity curves, the radial velocity curves of NGC 751 are characterized by large variations of more than 100 km s−1 along the slit.[5]
A large, diffuse tidal tail extends 20 arcsec (10 kpc) to the north-east of the pair.[5]
^ abcdefMadejsky, R. (1991). "Morphology and kinematics of the interacting elliptical galaxies NGC750 and NGC751 = ARP 166 - Velocity fields of tidally distorted elliptical galaxies". Astronomy and Astrophysics. 247: 348–356. Bibcode:1991A&A...247..348M.
^Sandage, A.; Bedke, J. (1994). The Carnegie Atlas of Galaxies. Volume I. Carnegie Institution of Washington. Bibcode:1994cag..book.....S.