[ Previous | Next | ADS ]

Properties of the Candidate Progenitor of SN 2011dh in M51

ATel #3401; W. Li, A. V. Filippenko (University of California, Berkeley), and S. D. Van Dyk (Spitzer Science Center, California Institute of Technology)
on 3 Jun 2011; 19:05 UT
Credential Certification: Alexei V. Filippenko (alex@astro.berkeley.edu)

Subjects: Infra-Red, Optical, Supernovae, Transient

Referred to by ATel #: 3406, 3432, 3433, 3641

We report further preliminary analysis of Hubble Space Telescope images of the SN 2011dh candidate progenitor (ATEL #3398, #3399; CBET #2736). The object has F435W (B) = 22.4 +/- 0.01 mag, F555W (V) = 21.84 +/- 0.01 mag, and F814W (I) = 21.22 +/- 0.01 mag. Assuming negligible host-galaxy reddening for the SN, and a distance modulus to M51 of 29.6 mag (Richmond et al. 1996, AJ, 111, 327), the object has M(I) = -8.4 mag, with color V - I = 0.6 mag, and B - V = 0.6 mag. If this bright source in the center of the SN location error radius is indeed the progenitor of SN 2011dh, its properties are similar to those reported for the progenitor of the Type II-L (or spectroscopically peculiar II-P) SN 2009kr (Elias-Rosa et al. 2010, ApJ, 714, L254; Fraser et al. 2010, ApJ, 714, L280), and it is consistent with a highly luminous yellow supergiant with an initial mass of 18-24 solar masses. Other possibilities are that (a) the bright source is a compact star cluster, with the progenitor of SN 2011dh being a member of the cluster, or (b) the bright source is unrelated to SN 2011dh, and the progenitor of SN 2011dh is obscured by this object. We encourage efforts to secure high-resolution images of the field to improve the astrometric precision.