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Title: The optical and infrared photometric evolution of the recent stellar merger, V1309 Sco

Nova Sco 2008 was recently shown to have resulted from the merger of the two stars in the contact binary V1309 Sco. This is the first stellar merger ever observed between two convective stars. We present archival data, new infrared photometry, and Hubble Space Telescope WFC3 imaging of V1309 Sco. Spitzer observations show that it had a large infrared excess in the 3.6 μm to 8 μm range more than a year before the merger. Standard color diagnostics of the pre-merger infrared colors place V1309 Sco in the same region where evolved stars with chemically complex mass loss are located. Since the nova outburst subsided in optical bandpasses in 2008, the merger remnant's brightness in optical bandpasses, near-IR bandpasses, and the Spitzer 3.6 μm and 4.5 μm channels has varied by several magnitudes and in complex ways. A temporary, strong increase in the reddening during 2010 suggests the occurrence of a dust formation event. We point out several peculiarities in the relative fluxes and time behavior of the optical and near-IR magnitudes, which could be explained if some of the photometric bandpasses in the 1-5 μm range are strongly affected by emission lines.
Authors:
 [1] ;  [2] ; ; ;  [3] ; ;  [4] ;  [5] ;  [6] ;  [7]
  1. California Institute of Technology, Pasadena, CA 91125 (United States)
  2. Spitzer Science Center, Caltech, MS 220-6, Pasadena, CA 91125 (United States)
  3. South African Astronomical Observatory/South African Large Telescope, P.O. Box 9, 7935 Observatory, Cape Town (South Africa)
  4. IACS/Department of Physics, Catholic University of America, Washington, DC 20064 (United States)
  5. Pisgah Astronomical Research Institute, Rosman, NC 28772 (United States)
  6. Australian Astronomical Observatory, P.O. Box 915, North Ryde, NSW (Australia)
  7. Department of Astrophysics, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan)
Publication Date:
OSTI Identifier:
22340046
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astronomical Journal (New York, N.Y. Online); Journal Volume: 147; 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; BINARY STARS; BRIGHTNESS; COLOR; DUSTS; EMISSION; MASS TRANSFER; NEAR INFRARED RADIATION; NOVAE; PHOTOMETRY; SPACE; STAR EVOLUTION; STELLAR WINDS; TELESCOPES; VISIBLE RADIATION