* Astronomy

Title: The Massive Progenitor of the Type II-Linear SN 2009kr
Authors: N. Elias-Rosa (1), S. D. Van Dyk (1), W. Li (2), A. A. Miller (2), J. M. Silverman (2), M. Ganeshalingam (2), A. F. Boden (3), M. M. Kasliwal (3), J. Vinko (4,5), J.-C. Cuillandre (6), A. V. Filippenko (2), T. N. Steele (2), J. S. Bloom (2), C. V. Griffith (2), I. K. W. Kleiserand (2), R. J. Foley (7,8) ((1) Spitzer Science Center, Caltech, (2) UC Berkeley, (3) Caltech, (4) U. Szeged (5) U. Texas, (6) CFHT corporation, (7) CfA, (8) Clay Fellow)
(Version v3)

We present early-time photometric and spectroscopic observations of supernova (SN) 2009kr in NGC 1832. We find that its properties to date support its classification as Type II-linear (SN II-L), a relatively rare subclass of core-collapse supernovae (SNe). We have also identified a candidate for the SN progenitor star through comparison of pre-explosion, archival images taken with WFPC2 onboard the Hubble Space Telescope (HST) with SN images obtained using adaptive optics (AO) plus NIRC2 on the 10-m Keck-II telescope. Although the host galaxy's substantial distance (~26 Mpc) results in large uncertainties in the relative astrometry, we find that if this candidate is indeed the progenitor, it is a highly luminous (M_V = -7.8 mag) yellow supergiant with initial mass ~18-24 M_sun. This would be the first time that a SN II-L progenitor has been directly identified. Its mass may be a bridge between the upper initial mass limit for the more common Type II-plateau SNe (SNe II-P) and the inferred initial mass estimate for one Type II-narrow SN (SN IIn).

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