[IAUC] CBET 1245: 20080209 : SUPERNOVAE 2008ab, 2008ac, 2008ad

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                                                  Electronic Telegram No. 1245
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 2008ab, 2008ac, 2008ad
     F. Yuan, University of Michigan; R. Quimby, California Institute of
Technology; M. D. Sisson, D. Chamarro, and C. Akerlof, University of Michigan;
and J. C. Wheeler, University of Texas, on behalf of the ROTSE collaboration,
report the discovery of three type-Ia supernovae in unfiltered CCD images
taken with the 0.45-m ROTSE-IIIb telescope at McDonald Observatory.

SN       2008 UT        R.A. (2000.0) Decl.     Mag.     Offset           z
2008ab   Jan. 30.23   11 34 45.92  +53 57 50.8  18.2                    0.069
2008ac   Jan. 30.27   11 53 45.18  +48 25 21.5  17.6   0".4 W, 0".5 N   0.053
2008ad   Jan. 30.42   12 49 37.15  +28 19 46.5  18.0   3".5 E, 1".7 N   0.054

A faint (r = 20.65) galaxy is seen at the position of 2008ab in the Sloan
Digital Sky Survey (SDSS); a finding chart for 2008ab is posted at
http://rotse.net/rsvp/j113445.9+535751/j113445.9+535751.jpg.  A finding chart
for 2008ac is at http://rotse.net/rsvp/j115345.2+482521/j115345.2+482521.jpg.
A finding chart for 2008ad can be found at the following website URL:
http://rotse.net/rsvp/j124937.2+281946/.
     A quick reduction of red-channel (530-1000 nm) spectra of 2008ab and
2008ac, obtained on Feb. 1.34 by E. Ofek with the Palomar 5-m telescope (+
Double Beam Spectrograph), shows narrow emissions lines, likely from the host
galaxies, that yield the redshifts tabulated above (that for 2008ac is in
agreement with the SDSS redshift for the apparent host).  Correcting for the
host redshifts, the minima of the Si II 635.5-nm features are blue-shifted by
10600 km/s and 11000 km/s, respectively, for 2008ab and 2008ac.
     A spectrum (range 420-890 nm) of 2008ad, obtained on Jan. 31.34 UT with
the 9.2-m Hobby-Eberly Telescope (+ Marcario Low-Resolution Spectrograph) by
S. Rostopchin and F. Deglman, is heavily contaminated by the host-galaxy
light; correcting for the recession velocity of the host galaxy (z = 0.054
from narrow H II region lines in the host), the minimum of the Si II 635.5-nm
feature is blue-shifted by 11700 km/s.


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                         (C) Copyright 2008 CBAT
2008 February 9                  (CBET 1245)              Daniel W. E. Green