[IAUC] CBET 1487: 20080901 : CI CYGNI

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                                                  Electronic Telegram No. 1487
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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CI CYGNI
     U. Munari and A. Siviero, Astronomical Observatory of Padova, INAF; and
G. Cherini, S. Tomaselli, M. Graziani, F. Tozzi, and S. Moretti, Asiago Novae
and Symbiotic Stars (ANS) collaboration, report that -- as also noted by
observers of the British Astronomical Association's Variable Star Section
and the AAVSO -- the symbiotic star CI Cyg is currently on the rise toward a
bright outburst.  The previous outburst peaked in brightness in July 1975
(cf. IAUCs 2788, 2965), when CI Cyg reached V = 8.6.  The mean values
obtained with various telescopes of the ANS collaboration between Aug. 31.85
and Sept. 1.05 UT are V = 9.66, B-V = +0.84, V-R_c = +0.89, and V-I_c = +2.11.
The corresponding long-term averages in quiescence that were obtained with the
same instruments are V = 11.2, B-V = +1.3, V-R_c = +1.5, and V-I_c = +3.3.
It is interesting to note that the outburst is occurring in coincidence with
egress from eclipse of the outbursting white dwarf orbited by the late-type
giant companion.  The center of the eclipse is predicted to have occured
between late June and mid August, according to the various ephemerides
available.


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                         (C) Copyright 2008 CBAT
2008 September 1                 (CBET 1487)              Daniel W. E. Green