- Cao, Yi;
- Kasliwal, Mansi M;
- Arcavi, Iair;
- Horesh, Assaf;
- Hancock, Paul;
- Valenti, Stefano;
- Cenko, S Bradley;
- Kulkarni, SR;
- Gal-Yam, Avishay;
- Gorbikov, Evgeny;
- Ofek, Eran O;
- Sand, David;
- Yaron, Ofer;
- Graham, Melissa;
- Silverman, Jeffrey M;
- Wheeler, J Craig;
- Marion, GH;
- Walker, Emma S;
- Mazzali, Paolo;
- Howell, D Andrew;
- Li, KL;
- Kong, AKH;
- Bloom, Joshua S;
- Nugent, Peter E;
- Surace, Jason;
- Masci, Frank;
- Carpenter, John;
- Degenaar, Nathalie;
- Gelino, Christopher R
The intermediate Palomar Transient Factory reports our discovery of a young supernova, iPTF13bvn, in the nearby galaxy, NGC 5806 (22.5 Mpc). Our spectral sequence in the optical and infrared suggests a Type Ib classification. We identify a blue progenitor candidate in deep pre-explosion imaging within a 2σ error circle of 80 mas (8.7 pc). The candidate has an MB luminosity of -5.52 ± 0.39 mag and a B-I color of 0.25 ± 0.25 mag. If confirmed by future observations, this would be the first direct detection for a progenitor of a Type Ib. Fitting a power law to the early light curve, we find an extrapolated explosion date around 0.6 days before our first detection. We see no evidence of shock cooling. The pre-explosion detection limits constrain the radius of the progenitor to be smaller than a few solar radii. iPTF13bvn is also detected in centimeter and millimeter wavelengths. Fitting a synchrotron self-absorption model to our radio data, we find a mass-loading parameter of 1.3×1012 g cm-1. Assuming a wind velocity of 103 km s-1, we derive a progenitor mass-loss rate of 3 × 10-5 M ⊙ yr-1. Our observations, taken as a whole, are consistent with a Wolf-Rayet progenitor of the supernova iPTF13bvn. © 2013. The American Astronomical Society. All rights reserved..