[IAUC] CBET 953: 20070506 : SUPERNOVA 2007ce

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                                                  Electronic Telegram No. 953
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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CBAT en CFA.HARVARD.EDU (science)
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SUPERNOVA 2007ce
     Further to IAUC 8622, R. Quimby, University of Texas, reports the
discovery of an apparent supernova (at mag about 17.4) in unfiltered
CCD images taken around May 4.14 UT using the 0.45-m ROTSE-IIIb
telescope at the McDonald Observatory.  SN 2007ce is located at R.A. =
12h10m17s.96, Decl. = +48o43'31".5 (equinox 2000.0), which is coincident
with an unresolved source of magnitude r about 22.2 in the Sloan
Digital Sky Survey catalogue that is itself at the edge (1".8 west and
3".2 south from the core) of a galaxy of magnitude r about 19.5.  The
new object was found by subtracting a co-addition of ROTSE-IIIb images
taken between 2005 Apr. 12 and 2007 Mar. 18 (limiting mag about 18.6),
and it was not detected in ROTSE-IIIb data from 2007 Apr. 24.12
(limiting mag about 17.8).  A spectrum (range 420-890 nm), obtained on
May 4.28 with the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution
Spectrograph) by S. C. Odewahn and E. Terrazas, shows 2007ce to be a
type-Ic supernova.  Strong, narrow emission lines from H-alpha, H-beta,
H-gamma, and O III 495.9- and 500.7-nm indicate a redshift of z = 0.046.
The spectrum is roughly similar to that of SN 2007bg a few days after
maximum light (CBET 927, 948), but with weaker absorption around rest
frame 605 nm.  Photometry at the Palomar 1.5-m telescope by A. Rau and
E. O. Ofek detected 2007ce at magnitudes g = 17.64 +/- 0.10 (May 4.421),
r = 17.46 +/- 0.10 (May 4.429), and i' = 17.40 +/- 0.15 (May 4.437).


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                         (C) Copyright 2007 CBAT
2007 May 6                       (CBET 953)               Daniel W. E. Green