COMMISSION 27 OF THE I.A.U.
              INFORMATION BULLETIN ON VARIABLE STARS
                           Number 1292

                                                    Konkoly Observatory
                                                    Budapest
                                                    1977 June 14


               FLARE ACTIVITY ON GL 569

We have observed a prominent double flare followed by 
extended lowlevel activity on GL 569 (alpha=14h52m08s, delta=+16d18'18";
1950) during a survey of nearby M dwarfs. Photometric observations 
with a time resolution of 3 seconds were made in the U-
band on the UBV system using the 1.5 m Hale Observatory telescope 
at Mt. Wilson on March 30 and 31, 1977 (UT). The sky background 
was measured at 3 minute intervals. The total integration
time was 5.0 hours on the object and 0.8 on the sky. The net
signal was ratioed to its preflare value and plotted in Fig. 1.
The double flare was remarkable in that an hour after the flare,
the signal was still 20% higher that its preflare level.
   Eggen (1968) has previously reported a 0.5 mag flare at
1.02 micron for GL 569. Subsequently, Asteriadis and Mavridis (1972)
observed a 20% flare in the B-band. The flare reported here, aside
from being more prominent and extended, was double. Mullan (1976)
interprets sympathetic flares with spacing of 2 to 4 minutes as
due to a Moreton wave propagating from a flare at a star spot
near one rotation pole to the other pole where it triggers a
second flare.
   We thank Mr. Howard Lanning of the Hale Observatories for
assisting with the observations. This paper presents the results
of one phase of research carried out at Jet Propulsion Laboratory, 
California Institute of Technology, under contract NAS 7-100,
sponsored by the National Aeronautics and Space Administration.


                      [FIGURE 1]

                            OLAV L. HANSEN *+
                            GLENN J. VEEDER *



References:

Asteriadis, G. and Mavridis, L.N. (1972) I.B.V.S. No. 712
Eggen, O.J. (1968) Astrophys. J. Suppl., 16, 49-96 [BIBCODE 1968ApJS...16...49E ]
Mullan, D.J. (1976) Astrophys. J. 204, 530-538 [BIBCODE 1976ApJ...204..530M ]


* Guest Investigator, Hale Observatories, California Institute
  of Technology and Carnegie Institution of Washington.

+ National Research Council
  Resident Research Associate