COMMISSION 27 OF THE I. A. U.
        INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1314

                                  Konkoly Observatory
                                  Budapest
                                  1977 July 29




        SPECTRAL CHANGES IN V1331 CYGNI (LkHalpha 120)*




   This unusual T Tauri star was included in a study of mass
loss from T Tauri stars by Kuhi (Ap.J. 140, 1409, 1964). He used
16 Angstrom/mm Lick spectra, in the case of V1331 Cygni unwidened 
because of the faintness of the star. The spectrum of V1331 Cygni
was described as essentially continuous, with superposed emission 
lines. The early Balmer lines of hydrogen and the K line
of ionized calcium showed P Cygni structure. Emission at the
CaII H line was quenched by the shortward-shifted absorption
component of Hepsilon. Among other emission lines were found the
4063 Angstrom and 4132 Angstrom lines of neutral iron typical of T Tauri
stars. No stellar absorption features were observed.
   From the strength and displacement of the Hgamma, Hdelta and K
absorption components Kuhi estimated the mass loss from V1331
Cygni to be of the order of 6x10-7Msun per year. This is a 
considerably higher value than found for any other T Tauri star.
In addition, Kuhi derived a mass of the star of about 4Msun, also
this higher than the masses of ordinary T Tauri stars. Although
it should be remarked that the precise values are dependent on
certain assumptions made by Kuhi for want of adequate data,they
clearly put V1331 Cygni in a class of its own among the more
thoroughly studied T Tauri stars.
   In August, 1976, two spectrograms of V1331 Cygni were 
obtained with the 1.52 m telescope of l'Observatoire de 
Haute-Provence equipped with the PEDISCOU (PEtite DISpersion COUde)
spectrograph and an RCA two-stage image tube. The reciprocal 
dispersion of these spectrograms is about 100 Angstroms/mm over the 
wavelength region 3700-5400 Angstrom.

* Based on observations made at l'Observatoire de Haute-Provence
 ( CNRS ).


    It was noted by Kuhi that the spectrum of V1331 Cygni had
shown no appreciable changes over a period of about four years.
In contrast to this the 1976 spectrograms show a marked weakening 
of the emission lines, and a strengthening of the absorption
components of the hydrogen lines, when compared to the spectrogram 
reproduced by Kuhi. Thus, no emission is seen at Hgamma and
Hdelta. The FeI 4063 Angstrom line is also absent, and may even be weakly
in absorption, whereas its companion line at 4132 Angstrom is present
in emission, although apparently weaker than in Kuhi's spectrum.
The other lines of this FeI multiplet (43) seem all to be in
absorption, as are a number of other lines, notably CaI 4227 Angstrom
and several TiII lines.
    The similarities between the earlier spectrograms of V1331
Cygni and the only existing spectrogram of V1057 Cygni before
its FU Orionis-like brightening in 1969-70 have been noted 
previously (Welin, Astron.Astroph. 49, 145, 1976). There is an 
interesting possibility that the spectral changes now observed in
V1331 Cygni may be signs of an imminent flare-up of this star.
However, occasional checks of the brightness of V1331 Cygni 
during the last year have so far not revealed any variations in
excess of those already known.





                           GUNNAR WELIN
                           Astronomiska Observatoriet
                           Box 515
                           S-751 20 Uppsala, Sweden