[IAUC] CBET 1754: 20090405 : SUPERNOVAE 2009cb, 2009cg-2009cx; PSN K0903-1, K0903-2, K0903-1; VARIABLE STARS

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                                                  Electronic Telegram No. 1754
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS en CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT en CFA.HARVARD.EDU (science)
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SUPERNOVAE 2009cb, 2009cg-2009cx; PSN K0903-1, K0903-2, K0903-1; VARIABLE STARS
     Further to CBET 1732, R. Quimby, California Insitute of Technology --
together with M. M. Kasliwal, S. B. Cenko, D. Fox, A. Gal-Yam, D. A. Howell,
S. R. Kulkarni, N. Law, D. Levitan, A. Mahabal, P. Nugent, E. O. Ofek, D.
Poznanski, and R. Thomas, on behalf of the larger "Palomar Transient Factory"
(PTF) collaboration -- report the discovery of numerous optical transients
with the Palomar Observatory 1.2-m Oschin Schmidt telescope (+ CFH12K
camera).  Imaging data were obtained on several nights between Mar. 17 and
28 with a g-band filter.  The transients were identified after subtracting
off reference templates (having mean limiting g-band magnitude 21.9) that
were constructed from imaging data obtained prior to Mar. 12.  Spectroscopic
follow-up was carried out on Mar. 27, 28, 29, 30, and 31 with the 9.2-m
Hobby-Eberly Telescope (+ LRS), the 5.1-m Palomar Hale telescope (+ DBSP),
and the 10.0-m Keck-I telescope (+ LRIS).  Included in the tabulation below
are the discovery date for each object and g-band magnitude at that time.
The confirmed supernovae below are all type-Ia events except for 2009cq
and 2009cv (possible type-II supernovae), 2009ct (type-II), and 2009cw
(possible type-IIn supernova).  SN 2009cb was independently discovered via
the Catalina Sky Survey (cf. CBET 1752).

SN       2009 UT         R.A. (2000.0) Decl.     Mag.     Offset          z
2009cb   Mar. 25.164   12 59 15.85 +27 16 41.3   19.1   1".7 W, 5".5 N   0.19
2009cg   Mar. 17.188   12 26 17.84 +48 26 49.5   20.9   5".3 W, 6".3 N   0.19
2009ch   Mar. 20.283   10 51 08.55 +74 05 23.2   20.5   3".9 E, 1".9 N   0.18
2009ci   Mar. 21.196   11 33 20.71 - 9 24 40.3   19.0   0".0 W, 0".2 N   0.12
2009cj   Mar. 21.216    9 45 30.46 + 6 32 25.0   17.8   0".2 W, 1".5 N   0.09
2009ck   Mar. 21.360    9 22 15.69 +45 44 53.4   19.5   0".0 E, 0".1 N   0.17
2009cl   Mar. 21.385   13 21 45.15 +42 33 06.2   20.2   0".8 W, 1".2 N   0.25
2009cm   Mar. 21.428   11 54 42.23 +55 18 10.7   20.1   0".1 W, 0".4 N   0.19
2009cn   Mar. 21.431   11 03 06.64 +50 09 36.3   19.8   0".6 W, 1".4 N   0.20
2009co   Mar. 21.435   12 24 35.31 +47 14 16.8   19.2   6".1 W, 1".2 N   0.16
2009cp   Mar. 25.152    9 15 12.73 +19 05 46.3   20.2   2".0 W, 2".9 S   0.22
2009cq   Mar. 25.161   11 46 50.12 +11 47 55.3   19.6   2".6 W, 0".7 S   0.11
2009cr   Mar. 25.163   11 18 06.46 +12 53 43.1   18.0   0".1 E, 1".3 N   0.14
2009cs   Mar. 25.262   14 15 19.36 +16 25 14.0   19.7   4".7 W, 4".5 S   0.17
2009ct   Mar. 26.251   13 15 23.15 +46 25 09.4   17.9   7".5 W, 3".9 S   0.06
2009cu   Mar. 26.251   13 29 12.64 +46 43 27.5   19.3   0".2 E, 0".9 N   0.10
2009cv   Mar. 27.161   11 42 13.88 +10 38 54.0   20.3   5".6 W, 5".2 N   0.15
2009cw   Mar. 28.404   15 05 01.97 +48 40 03.9   20.3   0".8 W, 0".7 N   0.15
2009cx   Mar. 28.416   12 24 39.20 + 8 55 59.2   20.5   1".6 W, 0".8 N   0.18

     Following are the discovery observations for three possible supernovae,
with their offsets from nearby possible host galaxies:

PSN       2009 UT         R.A. (2000.0) Decl.      Mag.      Offset
K0903-1   Mar. 21.186  11 16 34.27  + 3 32 02.8    20.1   0".2 W, 2".1 N
K0903-2   Mar. 26.209  14 30 50.42  +35 37 31.4    18.8   4".2 E, 3".3 S
K0903-3   Mar. 26.230  14 10 18.54  +16 53 38.8    19.0   4".7 E, 3".9 N

PSN K0903-1 has redshift z = 0.19.  PSN K0903-2 was not spectroscopically
confirmed; however, from its proximity to a galaxy in the Sloan Digital Sky
Survey catalogue (z = 0.03), it is likely to be a supernova.  Spectra of PSN
K0903-3 show a nearly featureless blue continuum.  Additional g-band
magnitudes:  PSN K0903-1, Mar. 25.160, 20.1; PSN K0903-2, Mar. 27.257, 18.9;
PSN K0903-3, Mar. 28.420, 18.8.

     Two variable stars were also found as tabulated below:

       Constellation   2009 UT          R.A. (2000.0) Decl.      Mag.
       Cam             Mar. 17.134    4 05 02.73  +73 24 54.2    18.5
       Cnc             Mar. 20.141    8 07 29.72  +15 34 41.8    16.9

The variable in Cam was detected on a single night over 2 hr; no source was
detected at that position during a spectroscopic observation on Mar. 31
with the Keck telescope (+ LRIS), and this significant fading suggests a
dwarf nova.  The transient in Cnc was spectroscopically determined to be a
cataclysmic variable star.
     All of these transient objects were first announced under their
preliminary PTF designations at http://www.astronomerstelegram.org/?read=2005
(though Quimby notes that their source labelled PTF09bf appears not to be a
true astronomical source).  The PTF project is described at website URL
http://www.astronomerstelegram.org/?read=1964.


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

                         (C) Copyright 2009 CBAT
2009 April 5                     (CBET 1754)              Daniel W. E. Green



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