COMMISSION 27 OF THE I. A. U.
           INFORMATION BULLETIN ON VARIABLE STARS
                          Number 987

                                      Konkoly Observatory
                                      Budapest
                                      1975 April 13


              NOTE ON THE RRab STAR AT ANDROMEDAE

     This star was studied by Tchumak [1] about ten years ago.
Using visual and photographic observations he arrived at the 
conclusion that the star had Blazko-effect. He determined a secondary
period of 82.75 days from the phase oscillations of the observed
maxima.
     In order to investigate the suspected light curve variation,
almost one thousand photoelectric observations were obtained in
yellow and blue light with the 24 in. and 20 in. telescopes of the
Konkoly Observatory between August 17, 1974 and January 20, 1975.
As comparison star we used BD +42deg4739 (V=9.465 and B-V=+0.372 s.
Sturch [2]).
    From our photoelectric observations no significant variations
have been found in phase or height of the 13 observed maxima. In
addition, our B and V observations are in very good agreement with
the observations obtained by Fitch et al. [3] in 1965.
    In the first two columns of the Table the times of the 
observed maxima and the O-C values are given, using the elements:

              2442343d.4204+0d.61691469.E

In the third and fourth columns the heights of the maxima relative
to the comparison star are listed in B and V light, respectively.

J.D.max.hel.    O-C   Delta{M_V} Delta{M_B} J.D.max.hel.  O-C Delta{M_V} Delta{M_B}

2442277.4110  +0.0005    0.96       0.99    2442367.4810 +0.0009   -      -
    304.5565  +0.0017    0.98       1.01    369.3290     -0.0018  0.96   0.99
    307.6405: +0.0012:    -          -      403.2644:    +0.0033: 0.96:  0.98:
    309.4887  -0.0014    0.95       0.99    422.3849     -0.0006  0.99   1.01
    319.3592  -0.0015    0.98:      1.00:   424.2338     -0.0024: 0.99   1.01
    343.4205  +0.0001    1.00       1.02    432.2550     -0.0011  0.98   1.00
    361.3110  +0.0001    0.98       1.00


                                                  K. OLAH

                                           Konkoly Observatory

[1] O.V. Tchumak, 1965, Peremenny Zvezdy 15, 569. [BIBCODE 1965PZ.....15..569T ]
[2] C. Sturch, 1966, Ap.J. 143. 774. and J. Kim, C. Sturch, 1967, PASP 79. 72 [BIBCODE 1966ApJ...143..774S ]
[3] W. S. Fitch, W. Z. Wisniewski and H.L. Johnson, 1967, Comm. Lunar
                  and Planetary Laboratory No. 71, Vol. 5, Part 2. [BIBCODE 1966CoLPL...5....3F ]




                              ERRATA CORRIGE

     In the IBVS No 974 owing to a misprint the mean error of
the colour of the comparison star of Nova RS Ophiuchi is given
uncorrectly:
     Instead of

                 B - V = + 1m.25 +- 0m.23

must be read

                 B - V = + 1m.25 +- 0m.03




                                              P. TEMPESTI