COMMISSION 27 OF THE I. A. U.
                  INFORMATION BULLETIN ON VARIABLE STARS
                              Number 3558

                                                        Konkoly Observatory
                                                        Budapest
                                                        28 January 1991
                                                        HU ISSN 0374 - 0676


                   SPORADIC PHOTOMETRY OF PLEIONE

   Pleione (HR 1180, BU Tau) is a renowned B8 V star in the Pleiades that over
the past century has variously been an ordinary B-star, a Be star, and a shell
star. A shell episode that began in 1972 was still continuing in 1987 (Goraya
et al. 1987), and at that time Dr Robert Garrison suggested to me that it would
be useful to monitor the star photometrically. I report here Stromgren
photometry obtained at this observatory in early 1987 and early 1988. It was
obtained differentially with respect to HR 1144 (18 Tau), another B8 V Pleiad
that is a Stromgren standard. Differential measures were added to the
Stromgren indices listed for the standard in The Astronomical Almanac to
produce the values in Table 1.

                          Table 1
                    Photometry of Pleione

HJD - 2440000      V       b-y      m1      c1     Beta

      6822.541   5.110   -0.033    0.121   0.815   2.605
      6837.560   5.089   -0.033    0.113   0.857   2.613
      6846.559   5.088   -0.033    0.126   0.884   2.602
      6871.587   5.095   -0.030    0.112   0.935   2.597
      7225.560   5.089   -0.013    -       -       -
      7231.536   5.079   -0.025    0.111   0.714   2.595
      7243.543   5.091   -0.012    -       -       -
      Means:     5.092   -0.026    0.117   0.841   2.602


   There seems evidence for real variability in the c1 index, but not much
elsewhere. However, the Beta index clearly reflects the presence of emission
partially filling the line; Pleione, from its membership in the Pleiades, has
Mv = +0.6, and from the Mv-Beta relation of Balona and Shobbrook (1984) one
would expect Beta ~2.83. The other indices, including c1, are about normal for
the spectral type, however.


                                               J.D. Fernie
                                               David Dunlap Observatory
                                               University of Toronto



References:

Balona, L.A., and Shobbrook, R.R., 1984, M.N.R.A.S. 211, 375. [BIBCODE 1984MNRAS.211..375B ]
Goraya, P.S., Tur, N.S., and Rautela, B.S., 1987, I.B.V.S. No. 3052.