M85 is extremely poor inneutral hydrogen[7] and has a very complex outer structure with shells and ripples that are thought to have been caused by amerger with another galaxy that took place between 4 and 7 billion years ago,[7] as well as a relatively young (<3 billion years old) stellar population on its centermost region, some of it in a ring, that may have been created by a latestarburst.[8] Like other massive, early-type galaxies, it has different populations ofglobular clusters. Aside from the typical "red" and "blue" populations, there is also a population with intermediate colors and an even redder population.[6] It is likely transitioning from being a lenticular galaxy into an elliptical galaxy.[6]
While indirect methods imply that Messier 85 should contain a centralsupermassive black hole of around 100 millionsolar masses,[9]velocity dispersion observations imply that the galaxy may entirely lack a central massive black hole.[10]
Twosupernovae and one luminous red nova have been observed in M85:
SN 1960R (TypeIa, mag. 13.5), was discovered by Howard S. Gates on 20 December 1960,[12] and independently discovered byLeonida Rosino on 18 January 1961.[13]
M85 OT2006-1 was discovered on the outskirts of the galaxy, by theLick Observatory Supernova Search (LOSS) on 7 January 2006. It was classified as aluminous red nova, the first to be identified as such.[14]
SN 2020nlb (Type Ia, mag. 17.436) was discovered by theATLAS telescope in Hawaii on 25 June 2020.[15][16] This supernova got as bright as magnitude 12.[17]
^"SN2020nlb".Transient Name Server.IAU. Retrieved30 November 2024.
^Townsend, A.; Smith, K. W.; Srivastav, S.; McBrien, O.; Smartt, S. J.; Gillanders, J.; Clark, P.; Fulton, M.; O'Neill, D.; Young, D. R.; McCollum, M.; Chen, T. W.; Anderson, J.; Denneau, L.; Flewelling, H.; Heinze, A.; Tonry, J.; Weiland, H.; Stalder, B.; Rest, A.; Wright, D. E. (2020)."ATLAS20qoq (AT2020nlb): Discovery of a candidate SN in MESSIER 85 (17 MPC)".Transient Name Server Astronote.126: 1.Bibcode:2020TNSAN.126....1T.
