COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                       Number 3041


                                        Konkoly Observatory
                                        Budapest
                                        30 June 1987

                                        HU ISSN 0374-0676



         UBV PHOTOMETRY OF EPSILON AURIGAE OUTSIDE ECLIPSE


   We made photoelectric photometry of Epsilon Aurigae on ten nights in March
and April 1986 with the 50-cm reflector of Hyogo University of Teacher Education.
Observations were carried out with UBV filters and an uncooled 1P21
photomultiplier tube. Every night we observed about ten standard stars from
Arizona-Tonantzintla Catalogue (Iriarte et al., 1965) to determine the atmospheric
extinction coefficients. One night during the observing period twenty
standard stars were observed and the transformation coefficients for converting
the instrumental system to the Johnson's system were estimated to be
epsilon = 0.0026, mu = 0.918 and psi = 1.015, where the notations are the
same as those

                       TABLE I

         MAGNITUDES AND COLORS OF epsilon AURIGAE

   Date         JD(Hel)    V      B      U      B-V    U-B
   (1986)       -2440000

   Mar.4        6494.098  2.94   3.50   3.97   0.56   0.47
   Mar.5        6494.957  2.93   3.49   3.98   0.56   0.49
   Mar.7        6497.019  2.95   3.51   3.97   0.56   0.46
   Mar.17       6507.030  2.95   3.53   3.94   0.58   0.41
   Mar.24       6514.029  2.94   3.48   3.95   0.54   0.47
   Apr.2        6523.014  2.95   3.51   3.93   0.56   0.42
   Apr.6        6526.996  2.97   3.52   3.97   0.55   0.45
   Apr.7        6527.978  3.00   3.56   3.98   0.56   0.42
   Apr.23       6544.000  3.08   3.67   4.07   0.59   0.40
   Apr.29       6549.964  3.21   3.69   4.14   0.48   0.45

of Henden and Kaitchuck (1982). We used eta Aur and lambda Aur as comparison stars.
The results are listed in Table I. From March 4 to April 2, 1986, the brightness
of epsilon Aur was approximately constant. After that, the star darkened by
DeltaV = 0.27 mag in about a month.

                                
                     FUMIO SATO*
                     AKIHIRO NISHIMURA
                     Hyogo University of
                      Teacher Education
                     Department of Science
                      Education
                     Yashiro, Hyogo 673-14
                     Japan


                     *
                     Present address
                     Tokyo Gakugei University
                     Department of Astronomy
                       and Earth Science
                     Koganei, Tokyo 184
                     Japan





 References:

Henden, A. A., and Kaitchuck, R. H. 1982, Astronomical
  Photometry (Van Nostrand Reinhold Co., New York),
  p. 37. [BIBCODE 1982asph.book.....H ]
Iriarte, B., Johnson, H. L., Mitchell, R. I., and
  Wisniewski, W. K. 1965, Sky and Telescope, 30, 25. [BIBCODE 1965S&T....30...21I ]