COMMISSION 27 OF THE I. A. U.
            INFORMATION BULLETIN ON VARIABLE STARS
                         Number 3404

                                          Konkoly Observatory
                                          Budapest
                                          12 December 1989

                                          HU ISSN 0374 - 0676


              1989 LIGHT CURVES OF BH VIRGINIS

  BH Virginis (BD-0d2769,HD121909) is a double-lined spectroscopic
eclipsing binary with cool components. The spectral types of the
components have been determined as GOV+G2V by Abt (1965) and as
F8IV-V+G2V by Koch(1967). Having late type magnetically active
components, the system's total light at maxima and/or minima is
expected to vary in time (Hoffmann, 1982; Budding and Gimenez,
1982). It has been observed photometrically by Kitamura et al. (1957),
Koch (1967), Sadik (1978), Hoffmann (1982) and Scaltriti et al.(1985).
In addition to ellipticity and reflection effects outside the eclipse
phases, an irregular fluctuation as a characteristic property of RS
CVn type systems has been noted as early as 1957 by Kitamura et al.
(1957). Scaltriti et al. (1985) have noted by comparing the existing
observations that the distortion wave is variable and migrates in
time, while Budding and Zeilik (1987) found a distortion wave of about
same shape with two minima at about the same phases from Sadik
(1978) and Scaltriti et al.'s (1985) data. True interpretation of the
light variations at different time scales requires a continuous
monitoring of the binary. Thus, we have included BH Vir in our program
of the photometric observations of short period binaries.
  The present observations of BH Vir were made on seven nights in
1989 using an EMI 9789QB photomultiplier attached to the 30 cm
Maksutov telescope of the Ankara University Observatory. The
differential observations in U, B and V colors were made with respect
to the comparison star BD-0d2770. Altogether 188, 190 and 187
differential magnitudes of BH Vir in V, B and U bandpass, respectively,


                            [FIGURE 1]

       Figure 1. The UBV observations of BH Vir in 1989


were obtained. The individual differential magnitude
determinations were corrected for differential atmospheric
extinction. The observations (in the sense variable minus
comparison) are shown in Figure 1 together with the color
curves. The phases were calculated by using the light element
from GCVS (1985), as

         Hel. JD Min I = 2443230.609 + 0.816877161 * E




   Two primary and one secondary eclipse minima have been secured
 during the observations. The new times of the minima are given in
 Table 1.

Table 1. The new times of minima of BH Vir

Hel. Min.          Filter   E         O-C      Remark
2447600+

15.5743 +-0.0006   U        11640     0.0093   Min.I
15.5732 +-0.0005   B        11640     0.0082   Min.I
15.5734 +-0.0013   V        11640     0.0084   Min.I
20.4754 +-0.0018   U        11646     0.0092   Min.I
20.4738 +-0.0004   B        11646     0.0076   Min.I
20.4738 +-0.0013   V        11646     0.0076   Min.I
58.4604 +-0.0027   U        11692     0.0097   Min. II
58.4580 +-0.0018   B        11692     0.0073   Min. II
58.4579 +-0.0013   V        11692     0.0072   Min. II



                       ETHEM DERMAN
                       AYVUR AKALIN
                       OSMAN DEMIRCAN

                   Ankara University Observatory
                   Science Faculty, Astronomy Department
                   Tandogan, 06100 Ankara / Turkey


References:

Abt, H. A. : 1965, Publ. Astron. Soc. Pacific, 77, 367. [BIBCODE 1965PASP...77..367A ]
Budding, E., Gimenez, A. : 1982, Proceedings of Third European IAU
   Conference, ESA SP-176, p. 169. [BIBCODE 1982ESASP.176..169B ]
Budding, E., Zeilik, M. : 1987, Astrophys. J., 319, 817. [BIBCODE 1987ApJ...319..827B ]
Hoffmann, M. : 1982, Astron. Astrophys. Suppl. Ser., 47, 561. [BIBCODE 1982A&AS...47..561H ]
Kitamura, M., Nakamura, T., Takahashi, C. : 1957, Publ. Astron. Soc.
   Japan, 9, 191. [BIBCODE 1957PASJ....9..191K ]
Koch, R. H. : 1967, Astron. J., 72, 411. [BIBCODE 1967AJ.....72..411K ]
Sadik, A. R. : 1978, Ph. D. Thesis Univ. of Manchester. [BIBCODE 1978PhDT.......296S ]
Scaltriti, F., Cellino, A., Busso, M. : 1985, Astron. Astrophys., 149, 11. [BIBCODE 1985A&A...149...11S ]