[IAUC] CBET 1866: 20090704 : SUPERNOVAE 2009hb AND 2009hc

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                                                  Electronic Telegram No. 1866
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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SUPERNOVAE 2009hb AND 2009hc
     D. Sand, Harvard-Smithsonian Center for Astrophysics (CfA) and Las
Cumbres Observatory Global Telescope Network; M. L. Graham and C. Bildfell,
University of Victoria; D. W. Just, S. Herbert-Fort, and S. Sivanandam,
Steward Observatory; C. J. Pritchet, University of Victoria; H. Hoekstra,
Leiden University; and D. Zaritsky, Steward Observatory, report that two
more type-Ia supernovae (cf. CBET 1864) were discovered on g'- and r'-band
images obtained at the Canada-France-Hawaii Telescope (+ Megacam).
Spectroscopic confirmation was obtained with GMOS-N on the Gemini telescope.
The publicly available Supernova Identification code of Blondin and Tonry
(2007, Ap.J. 666, 1024) was utilized for determining spectroscopic types,
indicating that 2009hb was around two months past maximum on June 16
and 2009hc was around three months past maximum on June 18.  The objects'
discovery magnitudes and spectroscopic redshift (z) are tabulated below:

 SN       2009 UT     R.A. (2000.0) Decl.       g'     r'      z
 2009hb   Apr. 23   15 22 29.65  +28 04 48.4   20.7   20.5    0.20
 2009hc   May  23   22 50 26.33  +10 54 41.7   23.0   22.4    0.08

Additional magnitudes for 2009hb:  May 22 UT, g' = 22.8, r' = 21.8.
Additional magnitudes for 2009hc:  June 17, g' = 23.4, r' = 23.1.  Neither
2009hb nor 2009hc apparently has a visible host galaxy down to magnitudes
g' about 24.0 and r' about 24.0.  Further imaging will be obtained of 2009hc
once it has faded, and 2009hc is likely associated with the galaxy cluster
Abell 2495 (z = 0.078), being 100" (148 kpc) from the cluster's "brightest
cluster galaxy"; pending further deep imaging, 2009hc is likely either a
genuine intracluster supernova (e.g., Gal-Yam et al. 2003, A.J. 125, 1087)
or is hosted by an extremely faint cluster member.


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                         (C) Copyright 2009 CBAT
2009 July 4                      (CBET 1866)              Daniel W. E. Green