KAIT Discovery of a Possible Supernova in the Kepler Field
ATel #4120; S. B. Cenko, A. V. Filippenko, M. Kandrashoff, K. Fuller, J. M. Silverman, and W. Li (UC Berkeley)
on 21 May 2012; 22:50 UT
Distributed as an Instant Email Notice Supernovae
Credential Certification: S. Bradley Cenko (cenko@astro.berkeley.edu)
Subjects: Optical, Supernovae, Transient
We report the discovery with the Katzman Automatic Imaging Telescope (KAIT) at Lick Observatory of a possible new supernova in the field of the Kepler spacecraft. The new object, dubbed PSN J19192793+4414509 (by the IAU), is located at (J2000.0) coordinates RA: 19:19:27.93, Dec: +44:14:50.9.
Following discovery on an unfiltered image obtained at 11:22 UT on 2012 May 19, KAIT autonomously began a sequence of triggered follow-up observations in the U, B, V, and clear (roughly R) filters beginning 4 minutes later. Using stars from the USNO-B1 catalog for reference, we measure an R-band magnitude at this time of R = 17.9. Previous KAIT imaging on 2012 May 15 revealed no emission at this location to a limiting magnitude of R > 18.8.
We obtained a CCD spectrum (range 340-1050 nm) of PSN J19192793+4414509 on May 21.45 UT with the Kast double spectrograph on the Shane 3-m telescope at Lick Observatory. The spectrum is dominated by a largely featureless blue
continuum, with superimposed narrow emission lines from the underlying host galaxy establishing a redshift of 0.042. These properties are suggestive of a very young Type II supernova. Further observations are encouraged to verify this classification.
