Astronomers are announcing today the discovery of a new class of stellar explosions. The finding is based on observations of a flash seen in the Virgo cluster in a galaxy known as Messier 85. According to Shrinivas R. Kulkarni, the team leader announcing the discovery of M85OT2006-1, the event is thought to have resulted from the merger of two ordinary stars 49 million years ago.
"The discovery of this enigmatic event is merely the proverbial tip of the iceberg for an emerging class of cosmic transients" - Kulkarni, the MacArthur Professor of Astronomy and Planetary Science at the California Institute of Technology. The team, which consists of astronomers from Caltech and the University of California at Berkeley, is announcing its findings in the current issue of the journal Nature.
Title: Spitzer Observations of the New Luminous Red Nova M85OT2006-1 Authors: A. Rau, S.R. Kulkarni, E.O. Ofek, L. Yan (revised v2)
M85OT2006-1 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, V4322 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 M85OT2006-1 six months post-eruption. We find that its 2.1-22 micrometer spectral energy distribution is best described by a black body with effective temperature T_eff=950 ±150 K and bolometric luminosity L=2.9 ±0.5x10^5 L_sun. Assuming spherical geometry, the black body effective radius, R=2.0 ±0.5x10^4 R_sun, and corresponding expansion velocity, v=870 ±260 km/s, 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 Infrared Nearby Galaxies Survey.
Title: Spitzer Observations of the New Luminous Red Novae M85\,OT2006-1 Authors: A. Rau, S.R. Kulkarni, E.O. Ofek, L. Yan
M85OT2006-1 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 M85OT2006-1 six months post-eruption. We find that its 2.1-22 micrometer spectral energy distribution is best described by a black body with effective temperature T_eff=950 ±150 K and bolometric luminosity L=2.9 ±0.5x10^5 L_sun. Assuming spherical geometry, the black body effective radius, R=2.0 ±0.5x10^4 R_sun, and corresponding expansion velocity, v=870 ±260 km/s, 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.