2009CBET.1950....1C

Further to CBET 1936, M. Catelan, Pontificia Universidad Catolica de Chile; A. J. Drake, S. G. Djorgovski, A. Mahabal, M. J. Graham, and R. Williams, California Institute of Technology; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the CRTS discovery of four apparent supernovae in unfiltered Catalina Sky Survey (CSS) images:

---------------------------------------------------------------------------— SN 2009 UT R.A. (2000.0) Decl. Mag. Offset ---------------------------------------------------------------------------— 2009ja Aug. 30.32 23 02 41.05 - 9 59 54.0 18.6 0".5 E, 1".0 N 2009jb Sep. 17.16 17 23 41.93 +30 29 50.2 17.4 3".1 E, 0".7 S 2009jc Sep. 17.37 1 02 43.63 -19 27 45.4 18.2 2009jd Sep. 19.33 0 29 56.04 - 4 34 50.7 18.4 12".6 E, 20".0 N ---------------------------------------------------------------------------—

Further CSS magnitude estimates for 2009ja: July 27.43 UT, [20.5; Aug. 26.33, 18.7; Sept. 10.27, 18.4; 21.25, 18.9. Further CSS magnitude estimates for 2009jb: July 31.25, [19.0; Aug. 20.20, 17.2. Nothing was visible at the position of 2009jc on a CCD image taken on 2008 Nov. 24.22 (limiting mag 20.4). A spectrogram (range 380-900 nm) of 2009jc was obtained with the SMARTS 1.5-m telescope on 2009 Sept. 23.25; cross-correlation with a library of supernova spectra using the "SuperNova IDentification" code (SNID; Blondin and Tonry 2007, Ap.J. 666, 1024) shows 2009jc to be a type-Ia supernova most similar to SN 1997dr at 17 days past maximum light. Further CSS magnitude estimates for 2009jd: 2008 Nov. 6.18, [19.8; 2009 Aug. 30.38, 18.6. Nothing is seen at the position of 2009jd in past co-added Palomar-Quest exposures to mag 21.5.