COMMISSION 27 OF THE I. A. U.
             INFORMATION BULLETIN ON VARIABLE STARS
                         Number 3187


                                             Konkoly Observatory
                                             Budapest
                                             16 May 1988

                                             HU ISSN 0374-0676


           VARIABILITY OF THE HERBIG Be STAR BHJ 71

  The star BHJ 71 as well as two other Herbig Be-Stars (HD 216629 (B2e) and
LkHalpha 350 (B2-5e)) are members of the Cep OB3 association. BHJ 71 is the 
star No. 71 in the catalogue compiled by Blaauw et al. (1959).
  125 UBVR observations of BHJ 71 were made at Maidanak Observatory between
July 1984 and January 1988. The observations were carried out with. the 48-cm
and 60-cm reflectors equipped with identical photometers. The star underwent
unique changes in the U-B colour. Figure 1 shows the light curve in V. The
observed amplitude of the light variability is 0.5m in B, V, and R bands, and
1 mag. in U.

                              [FIGURE 1]



  Figure 2 shows the position of the star on the two-colour diagram. The U-B
colour index increased up to ~+0.6m between July 1984 and mid-1987, and then
decreased.
   Five days before the beginning of the photometric observations on 23 July
1984, a spectrum of BHJ 71 was obtained with the 1-m Schmidt telescope of the


                              [FIGURE 2]


Byurakan Astrophysical Observatory using a 3 deg. objective prism. The spectral
class of BHJ 71 was estimated to be B2-3. Brodskaya (1953) estimated it as B0,
while Finkenzeller and Mundt (1984) published B0-B8. The latest spectral class,
B8, seems to be based on the estimation made by the Q-method (Blaauw et a1.,1959).
The same method was applied to our photometric observations, and we obtained
the same result for the minimum brightness. The analysis of the two-colour diagram
gives us different mean values of the extinction during the brightness maximum
and minimum, viz. EB-V max= 1.2 mag, EB-Vmin = 0.8 mag
  
  It has to be noted that there are no analogies between the light curves of
early type Ina irregular variables (including Herbig Ae/Be stars) and that of
BHJ 71.


N.D. MELIKIAN                        V.S. SHEVCHENKO
Byurakan Astrophysical Observatory   M.A. IBRAGIMOV
Byurakan, Armenia, USSR              S.D. JAKUBOV
                                     A.V. CHERNYSHEV
                                     Astronomical Institute
                                     A.N. Uz.SSR, Tashkent, USSR

References:

Blaauw, A., Hiltner, W.A., Johnson, H.L., 1959, Astrophys. J., 130, 69. [BIBCODE 1959ApJ...130...69B ]
Brodskaya, E.S., 1953, Izv. Kr. A.O., 10, 104. [BIBCODE 1953IzKry..10..104B ]
Finkenzeller, U., Mundt, R., 1984, Astron. Astrophys. Suppl. Ser., 55, 109. [BIBCODE 1984A&AS...55..109F ]