Electronic Telegram No. 1351
Central Bureau for Astronomical Telegrams
INTERNATIONAL ASTRONOMICAL UNION
M.S. 18, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
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CBAT@CFA.HARVARD.EDU (science)
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BF CYGNI
     T. Iijima, Astronomical Observatory of Padova, Asiago Station,
reports that, following the announcements of a brightening of the
symbiotic star BF Cyg via AAVSO and VSNET alerts, a high dispersion
spectrogram (range 435-612 nm; resolution 10000) was taken on Apr.
20.146 UT with an echelle spectrograph mounted on the 182-cm
telescope at the Mount Ekar station of the Astronomical Observatory
of Padova.  Spectra in the last observational season (Nov. 2007)
showed numerous emission lines of H I, He I, Fe II, [Fe II], [N II],
Na I, etc.  In contrast to them, the emission lines of He I, [Fe II],
and [N II] have disappeared in the new spectrum, and the other
lines have fairly weakened.  P-Cyg-type absorption components,
blue-shifted by about -40 km/s, have developed for Fe II and Na I
lines.  These spectral features confirm that BF Cyg has entered a new
explosive stage.


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      superseded by text appearing later in the printed IAU Circulars.

                         (C) Copyright 2008 CBAT
2008 April 23                    (CBET 1351)              Daniel W. E. Green