2009CBET.1760....1D

A. J. Drake, S. G. Djorgovski, A. Mahabal, R. Williams, and M. J. Graham, California Institute of Technology; A. S. Moskvitin, T. A. Fatkhullin, V. V. Sokolov, O. I. Spiridonova, and A. F. Valeev, Special Astrophysical Observatory (SAO), Russian Academy of Sciences; E. Sonbas, Cukurova University; S. B. Pandey, B. Kumar, and R. Roy, Aryabhatta Research Institute of Observational Sciences, Nainital; D. Y. Tsvetkov, Sternberg Astronomical Institute, Moscow State University; 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 discovery of a supernova in unfiltered Catalina Sky Survey (CSS) images:

---------------------------------------------------------------------------— SN 2009 UT R.A. (2000.0) Decl. Mag. Offset ---------------------------------------------------------------------------— 2009db Mar. 19.41 14 21 54.63 +26 01 02.0 18.4 0".9 W, 6".3 S ---------------------------------------------------------------------------—

Follow-up images, including some taken with the Palomar 1.52-m reflector (+ Gunn g, r, and i filters) and the SAO Zeiss-1000 1.0-m telescope (+ R filter), yield the following additional magnitudes for 2009db: Feb. 26.45 UT, [21.0 (CSS); Mar. 21.22, g = 18.6, r = 18.7, i = 19.0; Mar. 25.41, 18.5 (CSS); Mar. 28.07, R = 18.32; Mar. 29.98, R = 18.24; Apr. 1.93, R = 18.44; Apr. 2.28, 19.1 (CSS); Apr. 4.04, R = 18.55. A confirming spectrogram (range 600-1000 nm) was taken with the BTA 6-m telescope on Apr. 4 UT; with the aid of the Supernova Identification code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024), 2009db is found to be a type-Ia supernova, with a spectrum similar to that of SN 1999ee.