COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     NUMBER 624

                                      Konkoly Observatory
                                      Budapest
                                      1972 February 8


                   A NEW FLARE STAR IN CYGNUS


During the nights of 12-13, 13-14 and 16-17 in November 1971, we took five
plates centered at V 1057 Cygni with multiple exposures on each one. We used
Eastman Kodak 103aO plates behind an ultraviolet filter. The length of each
exposure was 10 minutes with a time interval of less than 1 second between the
exposures. On the first of the two plates (six different exposures in each)
obtained the night of November 13-14, a very conspicuous flare-up was
registered in a star that is rather faint at minimum. The rapid brightening of

                          [FIGURE 1]

this star occurred during the fourth exposure of this first plate, reaching
thus its maximum brightness. The star declined rapidly during the fifth and
sixth exposure, as is shown in Fig. 1. On the second multiple exposure plate
taken immediately after the first one mentioned, the star was not visible any
more.

The approximate right ascension and declination, the approximate ultraviolet
apparent magnitude during minima, and the Delta mU are given in Table I. Fig. 2
is a copy of a Tonantzintla Schmidt camera red plate and will serve as
identification chart.

Table I

Flare Star in Cygnus

Tonantzintla   R.A.        Dec.      Cygnus   Delta mU    Date of
   No.             (1950)              mU                Flare-up

   1       21^h00^m.5  +42deg07'.8     18.0     4.5      1971 XI/14

                         [FIGURE 2]

It is interesting to note, first, that this new flare star in Cygnus was
discovered in a rather small number of multiple ultraviolet exposure plates, 30
different exposures in all, covering a total of 5 hours of effective
observation; and second, that the star is located near the edge of a somewhat
obscure area south of the North America Nebula. As is well known, this region
is characterized by the existence - apart from the bright and dark nebulae - of
a good number of high luminosity stars, Be objects, T Tauri stars, and the
remarkable V 1057 Cygni star which before its outburst was known as an advanced
T Tauri type object. Because of the apparent magnitude and colors of this
new "rapid" flare star during minima and the possible spectral type that is
earlier than M, it seems highly probable that it is at the same distance as the
great majority of the stars mentioned before.


January 25, 1972

G. HARO
E. CHAVIRA
Instituto National de Astrofisica, Optica y Electronica
Tonantzintla, Mexico