During April 2013, a dramatic outburst was discovered at the core of NGC 2617,[13] and the spectral type was found to have changed to a Seyfert 1. An increase in X-ray emission was observed, followed by an increase in ultraviolet and then infraredluminosity.[4] This event can be modeled by X-ray radiation heating the accretion disk orbiting a supermassive black hole (SMBH) at the center of the galaxy. This was followed by emission at longer wavelengths from the heated disk.[4] An increase in luminosity between 2010 and 2012 may have cleared away dust in the inner part of the disk prior to the outburst, allowing a clearer view and changing the Seyfert type of the galaxy.[14] The SMBH has an estimated mass of 30.9+11.8 −8.5 million M☉.[3]
Additional outbursts were observed from 2016 to 2018, in between deep minima.[15]
^Sulentic, Jack W.; et al. (1973), The Revised New Catalogue of Nonstellar Astronomical Objects, Tucson: University of Arizona Press, Bibcode:1973rncn.book.....S.
^Boller, Th.; et al. (July 1992), "ROSAT all sky survey observations of IRAS galaxies.", Astronomy and Astrophysics, 261: 57–77, Bibcode:1992A&A...261...57B.
^Moran, Edward C.; et al. (October 1996), "Classification of IRAS-selected X-Ray Galaxies in the ROSAT All-Sky Survey", Astrophysical Journal Supplement, 106: 341, Bibcode:1996ApJS..106..341M, doi:10.1086/192341.
^Shappee, B. J.; et al. (April 2013), "ASAS-SN Discovery of a Strong AGN Outburst and Dramatic Seyfert Type Change in NGC 2617", The Astronomer's Telegram, 5010: 1, Bibcode:2013ATel.5010....1S.
^Oknyansky, V.; et al. (June 2018), "NGC 2617 brightens again after long very low state", The Astronomer's Telegram, 11703: 1, Bibcode:2018ATel11703....1O.
Further reading
Hoin, S.; et al. (December 2022), "Six Swift Observations of the CLAGN NGC 2617", The Astronomer's Telegram, 15804: 1, Bibcode:2022ATel15804....1H.