A Binary Progenitor for the Type IIb Supernova 2011dh in M51

BENVENUTO, OMAR G.; BERSTEN, MELINA C.; NOMOTO, KEN'ICHI

ASTROPHYSICAL JOURNAL

IOP PUBLISHING LTD

Lugar: Londres; Año: 2013 vol. 762 p. 74 - 84

0004-637X

We perform binary stellar evolutionary calculations following the simultaneous evolution of both stars in the system to study a potential progenitor system for the Type IIb supernova 2011dh. Pre-explosion photometry as well as light-curve modeling has provided constraints on the physical properties of the progenitor system. Here, we present a close binary system (CBS) that is compatible with such constraints. The system is formed by stars of solar composition with 16 Msun + 10 Msunon a circular orbit with an initial period of 125 days. The primarystar ends its evolution as a yellow supergiant with a mass of ~4 Msun, a final hydrogen content of ~(3-5)X10^{-3} Msun, and with an effectivetemperature and luminosity in agreement with the Hubble SpaceTelescope (HST) pre-explosion  observations of SN 2011dh. These results are nearly insensitive to the  adopted accretion efficiencyfactor beta. At the time of explosion, the companion star has aneffective temperature of 22,000-40,000 K, depending on the value ofbeta, and lies near the zero-age main sequence. Considering theuncertainties in the HST pre-SN photometry, the secondary star is only marginally detectable in the bluest observed band. CBSs, as opposed tosingle stars, provide a natural frame to explain the properties of SN2011dh.