COMMISSIONS 27 AND 42 OF THE IAU
             INFORMATION BULLETIN ON VARIABLE STARS
                          Number 3879

                                            Konkoly Observatory
                                            Budapest
                                            13 May 1993

                                            HU ISSN 0374 - 0676


               A NEW VARIABLE STAR GSC 4383.0384


Observing supernova 1993J in the evening April 16,1993 at 19:15 UT, Kamil
Hornoch and Jan Kysely (at 19:12 UT) independently noticed a brightness change
of a star plotted in a special AAVSO chart for SN 1993J at NGC 3031 (M81). The
star is some 9.7' north and 4.7' west with respect to the center of M81 galaxy.

The star's number in the Guide Star Catalog [1] is 4383.0384, alpha =
9h54m28.9s, delta = +69d13'22" (equinox 2000.0) its brightness is given
there as 10.80 mag. The star is not included in the General Catalogue of
Variable Stars (2) nor in the New Catalogue of Suspected Variable Stars (3).

Visual observation by K. Hornoch, J. Kysely and other visual observers will
be published in (4).

K. Hornoch's message arrived immediately at the N. Copernicus Observatory and
Planetarium in Brno, where the star was measured the same night by the
photometer (uncooled EMI 6256 photomultiplier) of our 0.4 m telescope and
variability of this star was definitely confirmed. In the course of
photoelectric measurements HD 86677 (V=7.876 mag, B-V=+0.510, Hipparcos Input
Catalogue [5]), was used as the comparison star, check stars were HD 85458, HD
85743 and GSC 4383.0565. Their V and B-V data indicate that the comparison
star is constant, whereas the GSC 4383.0384 exhibited apparent light
variations, when we measured it. Up to now we measured six nights and we
caught two maxima and two minima. The V amplitude the star can be estimated at
0.3 mag and period about dozen hours. More detailed information on the
photoelectric measurements of the new variable will be published later.


   Dalibor HANZL               Jan KYSELY
   N. Copernicus Obs.          Cs. Armady
   and Planetarium             258 01 VLASIM
   616 00 BRNO                 Czech Republic
   Czech Republic
   (E-mail: HANZLC@CSBRMU11)

                  Kamil HORNOCH
                  Paseky 392
                  664 31 Lelekovice
                  p. CESKA
                  Czech Republic

References:

[1] The Guide Star Catalogue, ver. 1.1, 1992, Space Telescope Science
  Institute, Baltimore.
[2] Kholopov, P.N., Samus, N.N., Frolov, M.S., Goranskij, V.P., Gorynya, N.A.,
  Karitskaya, E. A., Kazarovets, E.V., Kireeva, N.N., Kukarkina, N.P., 
  Medvedeva, G.I., Pastukhova, E.N., Perova, N.B., and Shugarov, S.Yu, 
  1987, General Catalogue of Variable Stars, Vol. III., Nauka, Moscow.
[3] Kukarkin, B.V., Kholopov, P.N., Artiukhina, N.M., Fedorovich, V.P.,
  Frolov, M.S., Goranskij, N.A., Gorynya, N.A., Karitskaya, E.A., Kireeva,
  N.N., Kukarkina, N.P.,
  Kurochkin, N.E., Medvedeva, G.I., Perova, N.B.,  Ponomareva, G.A., Samus',
  N.N. and Shugarov, S. Yu, 1982 New Catalogue of Suspected Variable Stars,
  Nauka, Moscow
[4] Contributions of the Nicholas Copernicus Observatory and Planetarium in
  Brno No. 31.
[5] Turon, C., et al., 1992, Hipparcos Input Catalogue. [BIBCODE 1992hicv.book.....T ]