2010CBET.2225....1C

Further to CBET 2224, 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; J. L. Prieto, Carnegie Observatories; E. C. Beshore and S. M. Larson, Lunar and Planetary Laboratory, University of Arizona; and E. Christensen, Gemini Observatory, report the CRTS discovery of two apparent supernovae in unfiltered Catalina Sky Survey (CSS) images:

---------------------------------------------------------------------------— SN 2010 UT R.A. (2000.0) Decl. Mag. Offset ---------------------------------------------------------------------------— 2010az Feb. 16.48 12 56 59.62 -17 37 35.5 17.7 3".9 W, 12".6 N 2010ba Mar. 21.33 11 58 20.68 +15 20 10.8 15.2 1".1 W, 1".3 S ---------------------------------------------------------------------------—

Nothing is visible at the position of 2010az on a CSS image from 2009 Apr. 18.27 (limiting mag 19.5). A spectrogram (range 380-920 nm) of 2010az was obtained with the SMARTS 1.5-m telescope (+ RCspec) on Mar. 23.28 UT. Cross-correlation with a library of supernova spectra using the "Supernova Identification" code (Blondin and Tonry 2007, Ap.J. 666, 1024) indicates that 2010az is most similar to the type-Ia supernova 1999ee at 41 days past maximum at z = 0.044. This is in excellent agreement with the host-galaxy redshift of 0.044 (Tustin et al. 2001, A.J. 122, 1289). The host galaxy of 2010ba, SDSS J115820.75+152012.1, has Gunn magnitudes g = 18.6, r = 18.1, and i = 17.9; the supernova is unresolved from the galaxy in CSS images. Further CSS magnitudes (supernova + host galaxy) for 2010ba: Feb. 14.34, 17.9; 19.40, 18.0; Mar. 5.31, 17.7; 13.26, 15.8.