The Ultraviolet Brightest Type Ia Supernova 2011de

Abstract

We present and discuss the UV/optical photometric light curves and absolute magnitudes of the Type Ia supernova (SN) 2011de from the Swift Ultraviolet/Optical Telescope. We find it to be the UV brightest SN Ia yet observed--more than a factor of ten brighter than normal SNe Ia in the mid-ultraviolet. This object is an extreme example of the differences seen in the ultraviolet for objects which do not appear remarkable in the optical. We find that the UV/optical brightness and broad light curves are broadly consistent with additional flux from the shock of the ejecta hitting a red giant companion. SN~2011de is either the first external interaction of a SN Ia discovered in the UV or an extreme example of the intrinsic UV variations in SNe Ia.

6 pages, including 4 figures and 1 table Submitted to ApJ Letters Swift/UVOT photometry available through the Swift Optical/Ultraviolet Supernova Archive (SOUSA) at http://swift.gsfc.nasa.gov/docs/swift/sne/swift_sn.html

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Cited by in corpus (2)

• A common-envelope wind model for Type Ia supernovae (I): binary evolution and birth rate
• Reddened, Redshifted, or Intrinsically Red? Understanding Near-Ultraviolet Colors of Type Ia Supernovae