Spitzer Observations of the New Luminous Red Novae M 85 OT 2006 - 1

M85 OT2006-1 is the latest and most brilliant addition to the small group of known Luminous Red Novae (LRNe). An identifying characteristic of the previously detected events (M31 RV, V432 Sgr & V838 Mon) was a spectral red-ward evolution connected with an emerging infrared component following the optical decay. Here we report on the discovery of a similar feature in Keck/NIRC and Spitzer photometry of M85 OT2006-1 six months post-eruption. We find that its 2.1−22 µm spectral energy distribution is best described by a black body with effective temperature T eff = 950 ± 150 K and bolometric luminosity L = 2.9 +260 −180 km s −1 , are remarkably similar to the properties of M31 RV 70 days after its eruption. Furthermore, we propose a search strategy for LRNe in the local Universe making use of the longevity of their infrared excess emission and discuss the expected number of events in the Spitzer Nearby Galaxies Survey.