Discovery and progenitor constraints on the Type Ia supernova 2013gy Academic Article uri icon


  • We present an early-phase g-band light curve and visual-wavelength spectra of the normal Type Ia supernova (SN) 2013gy. The light curve is constructed by determining the appropriate S-corrections to transform KAIT natural-system B- and V-band photometry and Carnegie Supernova Project natural-system g-band photometry to the Pan-STARRS1 g-band natural photometric system. A Markov chain Monte Carlo calculation provides a best-fit single power-law function to the first ten epochs of photometry described by an exponent of 2.16+0.060.06 and a time of first light of MJD 56629.4+0.10.1, which is 1.93+0.120.13 days (i.e., < 48 h) before the discovery date (2013 December 4.84 UT) and 19.10+0.120.13 days before the time of B-band maximum (MJD 56648.50.1). The estimate of the time of first light is consistent with the explosion time inferred from the evolution of the SiII6355 Doppler velocity. Furthermore, discovery photometry and previous nondetection limits enable us to constrain the companion radius down to Rc4R. In addition to our early-time constraints, we used a deep +235 day nebular-phase spectrum from Magellan/IMACS to place a stripped H-mass limit of < 0.018M. Combined, these limits effectively rule out H-rich nondegenerate companions.

published proceedings


altmetric score

  • 8.08

author list (cited authors)

  • Holmbo, S., Stritzinger, M. D., Shappee, B. J., Tucker, M. A., Zheng, W., Ashall, C., ... Zhao, X.

citation count

  • 19

complete list of authors

  • Holmbo, S||Stritzinger, MD||Shappee, BJ||Tucker, MA||Zheng, W||Ashall, C||Phillips, MM||Contreras, C||Filippenko, AV||Hoeflich, P||Huber, M||Piro, AL||Wang, XF||Zhang, J-J||Anais, J||Baron, E||Burns, CR||Campillay, A||Castellon, S||Corco, C||Hsiao, EY||Krisciunas, K||Morrell, N||Nielsen, MTB||Persson, SE||Taddia, F||Tomasella, L||Zhang, T-M||Zhao, X-L

publication date

  • January 2019