2009CBET.1958....1D

Further to CBET 1956, A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams, California Institute of Technology; M. Catelan, Pontificia Universidad Catolica de Chile; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the CRTS discovery of a supernova in unfiltered Catalina Sky Survey (CSS) images:

---------------------------------------------------------------------------— SN 2009 UT R.A. (2000.0) Decl. Mag. Offset ---------------------------------------------------------------------------— 2009jh Aug. 2.17 14 49 10.09 +29 25 10.4 18.9 7".8 W, 0".1 S ---------------------------------------------------------------------------—

The object was classified as a possible supernova and placed on public webpages on Aug. 2. Follow-up observations of 2009jh were made with the Palomar 1.5-m telescope using Gunn filters on Aug. 3.18 UT, yielding these magnitudes: g = 19.57, r = 19.51, and i = 20.06. Further CSS magnitudes for 2009jh: June 17.21 UT, [20.8; Aug. 29.15, 19.5. The object was independently discovered by Quimby et al. ("Palomar Transient Factory") on Aug. 11 (see http://lanl.arxiv.org/abs/0910.0059, where the object is noted as PTF09cwl), citing position end figures 10s.08, 11".4, who also obtained spectroscopic confirmation – showing this to be a very luminous supernova at z = 0.349, most resembling spectra of SN 2005ap, suggesting that the outburst is due to pulsational electron-positron pair-instability.