Radio detection of supernova 2004ip in the circumnuclear REGION of the luminous infrared galaxy iras 18293-3413

We report a radio detection of supernova SN 2004ip in the circumnuclear region of the luminous infrared galaxy IRAS 18293-3413 , using Very Large Array (VLA) observations at 8.4 GHz on 2007 June 11. SN 2004ip had been previously discovered at near-infrared wavelengths using adaptive optics observations, but its nature (core collapse or thermonuclear) could not be definitely established. Our radio detection, about 3 years after the explosion of the supernova, indicates a prominent interaction of the ejecta of SN 2004ip with the circumstellar medium, confirming that the supernova was a core collapse event (probably a Type II) and strongly suggesting that its progenitor was a massive star with a significant mass loss prior to its explosion. SN 2004ip has a 8.4 GHz luminosity of 3.5 x 1027 ergs s-l Hz-1, about 3 times as bright as SN 2000ft in NGC 7469 at a similar age; given its projected distance to the nucleus (-500 pc), it is one of the closest of all known radio SNe to a galaxy nucleus and one of the brightest radio SNe ever. © 2007. The American Astronomical Society, All rights reserved.