COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                      Number 2798

                                           Konkoly Observatory
                                           Budapest
                                           24 September 1985

                                           HU ISSN 0374 - 0676


          TIMES OF MINIMA AND NEW ELEMENTS OF GX LACERTAE


  GX Lacertae (BD + 56deg2855 = HD 240 055) was discovered as a probable eclipsing
binary by Uitterdijk (1934) on photographic plates. Its photometric elements were
first determined by Kreiner (1968). No more observations of GX Lac, either
photometric or spectroscopic, have been made since 1967.
  During the period July 1981 - November 1984 GX Lac was observed photoelectrically
with the 50 cm reflector at the Cracow Astronomical Observatory. The
observations were made using the standard V filter and the star "b" from the
Wright's chart of CO Lac (Wright, 1937) was used as a comparison star.
  From these data three times of minima, as given below, were determined using
the tracing-paper method.

J.D. hel               E         O-C1    O-C2      Remarks
2445189.486+/- .003   856       +0.2943 +0.0007    prim.
   5993.413+/- 0.05   982.5     +0.3264 -0.0105    sec.
   6009.312+/- .003   985       +0.3282 +0.0003    prim.

The O-C1 values were calculated using the elements:
  J.D. 243 9749.3973 + 6.3549d x E                        (Kreiner, 1968)

On the basis of these three minima, the period was corrected P = 6.355243d and
the O-C2 values were calculated from the new elements:
  J.D. 243 9749.3973 + 6.355243d x E
For the epoch of the photographic diminishing of brightness of GX Lac, published
by Uitterdijk (1934), O-C2=-0.04d, so the period seems to be correct and 
constant in time.

  The light curve of GX Lac and orbital elements will be published elsewhere.



  J.M. KREINER                                    MARIA KRURPINSKA-WINIARSKA
  Department of Physics                           M. WINIARSKA
  Higher pedagogical School                       Astronomical Observatory
  Cracow, Poland                                  of the Jagellonian University
                                                  Cracow, Poland

References:
Kreiner, J.M., 1968, I.B.V.S. No. 249
Uitterdijk, J., 1934, B.A.N. 7, 160 [BIBCODE 1934BAN.....7..159U ]
Wright, F.W., 1937, Harvard Ann., 89, 171 [BIBCODE 1937AnHar..89..171W ]