[IAUC] CBET 777: 20061220 : VARIABLE STAR IN CAMELOPARDALIS

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                                                  Electronic Telegram No. 777
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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VARIABLE STAR IN CAMELOPARDALIS
     W. Kloehr, Schweinfurt, Germany, reports his discovery of a variable
star (red mag about 15.2) on unfiltered CCD exposures taken on Dec. 16.16
UT with a Meade 0.25-m Schmidt-Cassegrain DSI-Pro II telescope.  The new
object is located at R.A. = 5h57m18s, Decl. = +68o32'26" (equinox 2000.0);
nothing appears at this location on an image by Kloehr taken on Nov. 27
(limiting mag about 18), though a USNO-B1.0 star of red mag 19.2 appears at
this location on a Palomar Sky Survey image.  Kloehr adds that confirming
CCD images of the variable were obtained by K. Torii (location unknown,
0.36-m telescope, Dec. 17.57, I_c = 15.2), and H. Maehara (location unknown,
Dec. 17.63, V = 14.95, B = 15.11), and O. Trontal (Oslo, Norway, 0.35-m
reflector, Dec. 17.85, unfiltered red mag about 15.2).  Kloehr also relays
that D. Boyd (West Challow, U.K.) observed the object for 2 hr via
unfiltered CCD photometry (0.35-m Schmidt-Cassegrain reflector), revealing
superhump-like modulations with a mean magnitude approximately 14.85, an
amplitude of 0.2 mag and a period (via Peranso) of 0.052 +/- 0.007 day --
suggesting that it is an SU UMa-type dwarf nova.
     M. Uemura and A. Arai, Hiroshima University, report that they
performed a time-series observation of this new variable between Dec.
18.5635 and 18.7895 UT with the "KANATA" 1.5-m telescope at
Higashi-Hiroshima Observatory.  The object was at V = 15.17 and J = 15.01
on Dec. 18.65324 and 18.65181, respectively.  The light curves clearly
show periodic modulations with amplitudes of about 1.2 mag in both the V
and J bands.  The period is estimated to be 0.0530(3) day.  In conjunction
with the blue color (V-J = +0.16), this observation strongly indicates
that it is a SU UMa-type dwarf nova, with the observed modulations being
superhumps.  The superhump period is the shortest among known systems.


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                         (C) Copyright 2006 CBAT
2006 December 20                 (CBET 777)               Daniel W. E. Green