Electronic Telegram No. 2225
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
CBAT Director:  Daniel W. E. Green; Room 209; Dept. of Earth and Planetary
 Sciences; Harvard University; 20 Oxford St.; Cambridge, MA  02138; U.S.A.
e-mail:  cbat@iau.org; cbatiau@eps.harvard.edu
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVAE 2010az AND 2010ba
     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.
     M. L. Graham, A. J. Maxwell, C. J. Pritchet, A. Parker, S. Sadavoy,
Department of Physics and Astronomy, University of Victoria; and D. D. Balam,
Dominion Astrophysical Observatory, National Research Council of Canada,
report that a spectrogram (range 390-703 nm, resolution 0.3 nm) of 2010ba,
obtained on Mar. 23.28 with the 1.82-m Plaskett Telescope of the National
Research Council of Canada, shows it to be a type-Ia supernova several days
before maximum light.  Cross-correlation with a library of supernova spectra
using the "Supernova Identification" code (Blondin and Tonry 2007, Ap.J. 666,
1024) indicates that 2010ba is most similar to the type-Ia supernova 2002bo
at 3 days pre-maximum.


NOTE: These 'Central Bureau Electronic Telegrams' are sometimes
      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 March 23                    (CBET 2225)              Daniel W. E. Green