Electronic Telegram No. 1631
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
IAUSUBS@CFA.HARVARD.EDU or FAX 617-495-7231 (subscriptions)
CBAT@CFA.HARVARD.EDU (science)
URL http://www.cfa.harvard.edu/iau/cbat.html


NEW CATACLYSMIC VARIABLE IN AQUARIUS
     H. Yamaoka, Kyushu University, reports the discovery by K. Itagaki
(Yamagata, Japan) of a previously unknown variable star on a wide-field
survey CCD image taken on Dec. 16.420 UT with a 0.21-m f/3 reflector.
Confirming CCD images taken on Dec. 16.424 with a 0.60-m f/5.7 reflector
show the variable's magnitude to be about 15.4 and its position to be R.A.
= 21h31m22.41s, Decl. = -0d39'36".8 (equinox 2000.0).  The star was fainter
than mag 17.5 on his survey image taken on 2007 Nov. 2.492, and fainter
than mag 16.7 on 2008 Dec. 1.420.  A faint blue star (magnitudes u = 21.6,
g = 21.4, r = 21.4, i = 21.7, z = 21.2) in the Sloan Digital Sky Survey
appears to be identical with Itagaki's variable.  Yamaoka adds that
photometry by Maehara (Kyoto University) and A. Miyashita (Tokyo) indicate
a short-period (about-100-min) modulation (amplitude about 0.1 mag), which
indicates that this variable is a SU UMa-type dwarf nova.  Following
posting on the Central Bureau's unconfirmed-objects webpage, R. A. Koff
(Bennett, CO, U.S.A.) writes that his unfiltered CCD images yield position
end figures 22s.41, 37s.0 (with a USNO-B1.0-catalogue star of mag about 21
at position end figures 22s.35, 36".9) and the following approximate
magnitudes (averaged over about 1 hr) for the variable:  Dec. 18.02, 14.2
(B-V approximately +0.01); 20.06, 14.1; 23.06, 14.6; 25.06, 14.8.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 December 25                 (CBET 1631)              Daniel W. E. Green