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Title: THE VERY YOUNG TYPE Ia SUPERNOVA 2013dy: DISCOVERY, AND STRONG CARBON ABSORPTION IN EARLY-TIME SPECTRA

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 {sub 0} ≲ 0.25 R {sub ☉}, 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 M{sub B} = –18.72 ± 0.03 magmore » ∼17.7 days after first light.« less
Authors:
; ; ; ; ; ; ; ;  [1] ; ;  [2] ;  [3] ;  [4] ; ;  [5] ;  [6] ;  [7] ;  [8] ;  [9] ;  [10] more »; « less
  1. Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States)
  2. Department of Astronomy, University of Texas, Austin, TX 78712 (United States)
  3. Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)
  4. Department of Physics, Tsinghua University, Beijing 100084 (China)
  5. Las Cumbres Observatory Global Telescope Network, 6740 Cortona Drive, Suite 102, Santa Barbara, CA 93117 (United States)
  6. Monte Agliale Observatory, Borgo a Mozzano, Lucca, I-55023 Italy (Italy)
  7. Astrophysics Science Division, NASA Goddard Space Flight Center, Mail Code 661, Greenbelt, MD 20771 (United States)
  8. Dominion Astrophysical Observatory, Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada)
  9. Carnegie Observatories, Las Campanas Observatory, Colina El Pino, Casilla 601 (Chile)
  10. Physics Department, Texas Tech University, Lubbock, TX 79409 (United States)
Publication Date:
OSTI Identifier:
22364135
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal Letters; Journal Volume: 778; Journal Issue: 1; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ASTROPHYSICS; CARBON IONS; COMPARATIVE EVALUATIONS; DETECTION; DIAGRAMS; EMISSION SPECTRA; EV RANGE; SUPERNOVAE; VISIBLE RADIATION; WHITE DWARF STARS