NGC 4688
NGC 4688 is a barred spiral galaxy in the constellation of Virgo. Its velocity with respect to the cosmic microwave background is, which corresponds to a Hubble distance of. However, five non-redshift measurements give a much closer mean distance of. It was discovered by German-British astronomer William Herschel on 17 April 1786.
NGC 4688 has a possible active galactic nucleus, i.e. it has a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that this luminosity is not produced by the stars. It is also a LINER galaxy, i.e. a galaxy whose nucleus has an emission spectrum characterized by broad lines of weakly ionized atoms.
M49 group
According to A. M. Garcia, NGC 4688 is a member of the M49 group. This group includes 63 galaxies from the New General Catalogue, including Messier 49, Messier 85, NGC 4516, Messier 60, and 20 galaxies from the Index Catalogue.Supernova
One supernova has been observed in NGC 4688:- SN 1966B was discovered by D. Ya. Martynov on 12 February 1966. Howard S. Gates had photographed it earlier, on 25 January 1966, but he suspected the object might be a minor planet, and delayed the announcement until a confirmation picture could be taken, thus losing credit for the discovery.