COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 1972

                                  Konkoly Observatory
                                  Budapest
                                  1981 June 1

                                  HU ISSN 0374-0676



     EXTRAGALACTIC NOVA OR UNUSUAL U Gem-TYPE VARIABLE?


  A new variable star: R.A.=10h31m19s, Dec.=+31d24'(1950),
l=197.0d, b=+59.8d, has been found by one of us (L.Z.) during 
inspection on the Carl Zeiss, Jena blinkcomparator a pair of B-plates.
of a field near SA 54. The star occurs to be visible on several
other photographs taken on April 1980 the same week as on the
discovery plate with the Schmidt telescope of the Radioastrophysical 
Observatory at Baldone. B- and V- magnitudes of the variable
object are given in Table I. They are measured in the system of
magnitudes of the comparison stars, partly presented in Table II.
On other 138 B- and 134 V-photographs (limiting magnitude B~18.5,
V~17.5) obtained between March 1970 and May 1979, and after 1980
May 5 the star is not visible. According to A.S. Sharov there are
no traces of the star either on the Palomar Observatory Sky Survey
charts or on seven plates of the region from Sternberg Astronomical
Institute plate collection taken in 1952-53 and 1974.
  Thus the amplitude of the observed outburst was at least 5 mag
and it lasted not less than 7 days. If the object is nova, it
belongs, probably, to the fast novae (light decline 0.2 mag/day)
and was observed not very long after its maximum light. Then it
is placed beyond the boundaries of our Galaxy.
  If the object is a cataclysmic variable of U Gem-type, then
either its outburst was exceptionally large or its mean period
between outbursts was extraordinarily long.
  To decide between the two alternatives the search for the
star on plates of the respective region of the sky taken at other
observatories would, probably, help.
  The variable is indicated on the finding chart (12x12 arcmin)
together with the comparison stars according to Table II.


                         [FIGURE 1]

 
                  Table I
Date             B       Date             V
(UT)             (mag)   (UT)             (mag)
1980 Apr.11.85   15.87   1980 Apr.12.85   15.97
Apr.11.88        15.73   Apr.16.82        17.43
Apr.12.97        16.09   Apr.19.90        17.13
Apr.14.89        16.36
Apr.15.93        16.96
Apr.16.85        17.05
Apr.17.91        17.20
Apr.18.96        17.40


                       Table II
Star   B       V       Star       B        V
2      14.91   14.22   10         17.05   15.95
4      15.35   14.66   13         17.35   16.01
5      15.75   15.25   15         17.48   15.98
7      15.89   14.79   17         17.63   16.72
9      16.18   15.33   20         18.67   17.28


                      A. ALKSNIS, L. ZACS
                      Radioastrophysical Observatory,
                      Latvian Academy of Sciences
                      Riga, Latvia, U.S.S.R.