COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1346

                                    Konkoly Observatory
                                    Budapest
                                    1977 October 6




          GL 851.1 - ANOTHER BY Dra-TYPE STAR ?



    According to UBV photometry by this author (Krisciunas 1976-
1977, JAAVSO 5, 74) the star Gl 851.1 (Gliese 1969, Veroffentl.
Astron.-Rechen Inst. Heidelberg No. 22) is most likely a dK5e
star lying 1 magnitude below the main sequence in the colour-
magnitude diagram. It has a (mean) apparent magnitude V=10.12
and a B-V of +1.17. A small variation of 0.03 mag in V was 
observed, using BD +30d4634 (V=10.15, B-V=+1.36) as a comparison
star. Also, the star was monitored visually for flares for a
total of 24 hours on 7 nights from September 1975 to September
1976 with a 15 cm reflector. No flares (DeltaV>~0.1 mag) were noted.
    In addition to this, Gl 851.1 has been spot checked visually 
on 34 other nights. Normally, one can tell that Gl 851.1 is
just noticeably brighter than BD +30d4634. However, on one night
the reverse was apparently the case. At 0430 UT on 20 September
1977 the red dwarf star was observed to be at least 0.1 magnitude
fainter than BD:+30d4634. By 0450 UT it was back to "normal".
    It is well known to visual variable star observers that
red stars grow brighter with prolonged observations. The possible 
variation of Gl 851.1 on 20 September 1977 could not have
been the result of this phenomenon, as the comparison star is
0.2 magnitudes redder.
    Red dwarf stars with emission line spectra can be flare
stars or BY Dra-type spot stars (Bopp and Espenak 1977, preprint).
It appears that Gl 851.1 is not an active flare star, but it
could likely be a BY Dra-type star. It would be of value to
recheck its spectral type and obtain more UBV photometry.
Gl 851.1, in Pegasus, is a fall object.

              Finder Chart for Gl 857.1

                1950 RA 22h 9m 53s
                1950 Dec +31d19'12"

                    [FIGURE 1]


Star            V      B-V     U-B  Number of
                                   observations
BD +30d4629    9.90   +1.62   +1.7   1
Gl 851.1      10.12   +1.17   +1.1   2
BD +30d4634   10.15   +1.36   +1.5   2

Photometry done with Leuschner Observatory 76 cm reflector,
1-3 August, 1975.





                              K. KRISCIUNAS

                              NASA/Ames Research Center
                              Mail Stop 248-1
                              Moffett Field
                              California 94035
                              U.S.A.