The very young type Ia supernova 2013dy: Discovery, and strong carbon absorption in early-time spectra

  • Weikang Zheng
  • , Jeffrey M. Silverman
  • , Alexei V. Filippenko
  • , Daniel Kasen
  • , Peter E. Nugent
  • , Melissa Graham
  • , Xiaofeng Wang
  • , Stefano Valenti
  • , Fabrizio Ciabattari
  • , Patrick L. Kelly
  • , Ori D. Fox
  • , Isaac Shivvers
  • , Kelsey I. Clubb
  • , S. Bradley Cenko
  • , Dave Balam
  • , D. Andrew Howell
  • , Eric Hsiao
  • , Weidong Li
  • , G. Howie Marion
  • , David Sand
  • Jozsef Vinko, J. Craig Wheeler, Jujia Zhang

Research output: Contribution to journalArticlepeer-review

97 Scopus citations

Abstract

The Type Ia supernova (SN Ia) 2013dy in NGC 7250 (d ≈ 13.7 Mpc) was discovered by the Lick Observatory Supernova Search. Combined with a prediscovery detection by the Italian Supernova Search Project, we are able to constrain the first-light time of SN 2013dy to be only 0.10 ± 0.05 days (2.4 ± 1.2 hr) before the first detection. This makes SN 2013dy the earliest known detection of an SN Ia. We infer an upper limit on the radius of the progenitor star of R 0 ≲ 0.25 R , consistent with that of a white dwarf. The light curve exhibits a broken power law with exponents of 0.88 and then 1.80. A spectrum taken 1.63 days after first light reveals a C II absorption line comparable in strength to Si II. This is the strongest C II feature ever detected in a normal SN Ia, suggesting that the progenitor star had significant unburned material. The C II line in SN 2013dy weakens rapidly and is undetected in a spectrum 7 days later, indicating that C II is detectable for only a very short time in some SNe Ia. SN 2013dy reached a B-band maximum of MB = -18.72 ± 0.03 mag ∼17.7 days after first light.

Original languageEnglish (US)
Article numberL15
JournalAstrophysical Journal Letters
Volume778
Issue number1
DOIs
StatePublished - Nov 20 2013
Externally publishedYes

Keywords

  • supernovae: general
  • supernovae: individual (SN 2013dy)

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'The very young type Ia supernova 2013dy: Discovery, and strong carbon absorption in early-time spectra'. Together they form a unique fingerprint.

Cite this