COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                     Number 2191

                                 Konkoly Observatory
                                 Budapest
                                 1982 August 25

                                 HU ISSN 0374-0676





        CSV 6984 - A NEW W UMa TYPE VARIABLE STAR



  The variable BV 97 = CSV 6984 = BD +37d2356 was discovered
by Kippenhahn (1955). Filatov (1960) suspected W UMa type 
variability but light elements has not been found. This investigation 
was undertaken with the aim of classification of the variable 
and determination of light and orbital elements of the
binary. In May 1980, photoelectric observations of CSV 6984
were made in the UBV system at Crimea Station of the Sternberg
Institute. The measurements were made using a 60 cm reflector
equipped with a photon counting photometer (Lyuty, 1971).
HD 113730 served as comparison star (Westerlund, 1963). About
300 observations in V and B bands were obtained and a few in
U band. The mean error of a single observation is 0.01m. The
light and colour curves are shown in Figure 1.

                      [FIGURE 1]

  Four moments of minima were determined from the observations:
  JD.hel. = 2444365.445 (II), 367.559 (I), 370.439 (II) and
374.4732 (I). The light elements are:
  JD.hel. Min I = 2444365.2497 + 0.38416d E.

The period could not be determined correctly enough for the short
observational set. Therefore, all published epochs of minima
could not be represented with a common period.
  Least-squares solutions were made for the light at the maxima
according to the formula:

             1 = A_0 + A_1 cos Theta + A_2 cos 2Theta

The Russell - Merill method (1952) was used to calculate the
rectified intensities. An analysis of the light curves using
Lavrov's computer code (1976) was made. The orbital elements of
the binary are given in Table I.


                  Table I

Element     V-solution   B-solution
               occ         occ
    x          0.6         0.6        adopted
k=a_2/a_1      0.66        0.76       +-0.16
  a_2          0.33        0.35       +-0.06
   i           76d         77d        +-3d
  L_1          0.70        0.68       +-0.11

  As the present solution is unreliable, more detailed 
investigations are needed.


                 G.V. ZHUKOV

           Department of Astronomy
           Kazan University
           KAZAN 422526 (Tatarskaja ASSR)
           U.S.S.R.





References:

Filatov G.S., 1960, Astron. Circ. No. 215, 21 [BIBCODE 1960ATsir.215...20F ]
Kippenhahn R., 1955, Kleine Veroff. Bamberg No. 11
Lavrov M.I., 1976, Variable Stars, Suppl., 2, 349 [BIBCODE 1976PZP.....2..349L ]
Lyuty V.M., 1971, Sternberg Inst. Reports, No. 182, 30
Russell H.M., Merill J.E., 1952, Princeton Contr., No. 26 [BIBCODE 1952deeb.book.....R ]
Westerlund B.E., 1963, MNRAS, 127, 83 [BIBCODE 1963MNRAS.127...83W ]