COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                      Number 1797

                                  Konkoly Observatory
                                  Budapest
                                  1980 May 30


  GLIESE 83.3: NOT A RED DWARF, BUT AN UNUSUAL VARIABLE NEVERTHELESS


Quite recently Olah (1980) reported photoelectric photometry of the red star
Gliese 83.3 (=BD +61d366 = HD 12208) which showed a roughly sinusoidal light
curve with an amplitude of 0.12m in B and V, with period P=2.825d. On the
basis of its photometric characteristics and its inclusion in Gliese's
catalogue of nearby stars, Olah claimed the star was a BY Draconis variable.
The spectral type (from an objective prism plate) given in Gliese's catalog is
dK5, though no trigonometric parallax has been measured for this star.

It is the purpose of this note to point out that Gliese 83.3 is not a dwarf at
all, but rather a giant of type M3-4. The variability of this star then
becomes more of a puzzle.

Petit (1976) had suggested that Gliese 83.3 might be a likely BY Dra star, and
in 1976 we obtained several spectra (dispersion 40 A/mm) of the red region
specifically to search for H_alpha emission, a common characteristic of BY Dra
stars. Our spectrograms of Gliese 83.3 show nothing resembling a K-M dwarf -
the TiO bandheads are very strong and no H_alpha emission is present. Our
spectra are a close match to that of HR 3319, of spectral type M3III, or
perhaps a shade later. The spectral type for Gliese 83.3 is then M3-4III.
No other peculiarities are visible in the red. Apparently the previous
spectral type is in error. We note also that the proper motion of this star
given in the SAO catalogue is quite small [(mu(alpha)=-0.0002s,
mu(delta)=+0.002"], in accord with a giant classification.

However, anomalies still remain. The photometric variability is rather
difficult to understand; irregular or semi-regular variability should take
place on a much longer time-scale that the 2.8d period Olah reports. The
(B-V) color of +1.70 is about a tenth of a magnitude redder than we might
expect for a giant of this spectral type. Further photometry of this star is
clearly in order.


BERNARD W. BOPP
Physics and Astronomy
The University of Toledo
2801 W. Bancroft
Toledo, OH 43606

References:

Olah, K. 1980, Inf. Bull. Var. Stars No. 1765.
Petit, M. 1976, Inf. Bull. Var. Stars No. 1135.