Electronic Telegram No. 2164
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@cfa.harvard.edu; dwe_green@eps.harvard.edu
URL http://www.cfa.harvard.edu/iau/cbat.html


SUPERNOVAE 2009mx AND 2009my
     D. Milisavljevic and R. Fesen, Dartmouth College, report that a low-
dispersion spectrum (range 430-790 nm) of 2009mx (cf. CBETs 2095, 2120),
taken on Feb. 6.4 UT with the 2.4-m Hiltner telescope (+ CCDS) at MDM
Observatory, supports a type-Ia supernova classification.  Comparison
with a library of supernova spectra using the "Supernova Identification"
tool (SNID; Blondin and Tonry 2007, ApJ., 666, 1024) provides a good match
with the type-Ia event 1991bg at approximately 54 days post-maximum light.
Spectra of 2009my (CBETs 2095, 2120) show it to be a type-II supernova
approximately 2 months after maximum light; SNID comparison templates best
match the type-IIP event 2006bp at 65 days post-maximum.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2010 CBAT
2010 February 7                  (CBET 2164)              Daniel W. E. Green