NGC 5084
NGC 5084 is a Seyfert 2 lenticular galaxy in the constellation of Virgo. It is located at a distance of about from Earth, which, given its apparent dimensions using the 90% total light definition, means that NGC 5084 is across. It is one of the largest galaxies|largest] and most massive galaxies in the Virgo Supercluster. William Herschel discovered it on March 10, 1785. It is a member of the NGC 5084 Group of galaxies, which is a member of the Virgo II Groups, a series of galaxies and galaxy clusters strung out from the southern edge of the Virgo Supercluster. The galaxy is seen nearly edge-on, with inclination 86°, and features a warped disk and large quantities of HI gas extending along the disk, probably accumulated after multiple accretions of smaller galaxies. NGC 5084 also possess an active galactic nucleus.
Mass and size estimates
NGC 5084 is a very massive system, with a high rotational speed of about 328 km/s. It is categorised as a supermassive disk galaxy. Gottesen estimated based on the rotational speed that the mass of NGC 5084 is and its radius to be for an estimated distance of. Gottesman et al. using the same method adopted as distance the and calculated the mass of NGC 5084 to be. Koribalski et al. measured the rotational speed of NGC 5084 to be 334 km/s and calculated its mass to be and its radius was estimated at. Carrignan et al. measured the velocity differences and projected separations of nine galaxies they identified as satellites of NGC 5084 and using different equations they estimated the mass of NGC 5084 to be between and, which was at that time the highest mass ever derived for a disk galaxy. They estimated the optical diameter of NGC 5084 to be.An estimation of NGC 5084's size using the 90% total light definition yields a very substantial apparent diameter of 1,949.84 arcseconds, which corresponds to a diameter of assuming the currently accepted distance to the galaxy. This would make it one of the largest known lenticular and supermassive disk galaxies.