COMMISSION 27 OF THE I. A. U.
         INFORMATION BULLETIN ON VARIABLE STARS
                    Number 3122


                                    Konkoly Observatory
                                    Budapest
                                    22 December 1987

                                    HU ISSN 0374-0676


            A NEW VARIABLE STAR IN CASSIOPEIA
                                       
 In an observational program on the eclipsing binary AB Cas, BD + 70 188 was
used as the comparison star (also used by Ando, 1980) and SAO 4710 (BD+70 199=
HD 16439) as the check star. The observations showed that while BD + 70 188
kept a nearly constant brightness, SAO 4710 presented an undoubted photometric
variability. This last star is not present in any of the variable star 
catalogues, hence it has to be considered as a new variable star. SAO 4710 was 
observed three nights in November 1987 with the 75 cm reflector at the "Sierra
Nevada" Observatory (Spain) in the Stromgren four colours. Figure 1 shows the
light curve in the v filter for November 17 th. In a preliminary Fourier


                              [FIGURE 1]

 Figure 1. - Light curve in the v filter at November 17th, with E = SAO
 4710 and C1 = BD +70 188. The magnitudes are in the instrumental system.


analysis of these light curves we could verify that SAO 4710 is a monoperiodic
pulsator with an amplitude of 0.041 mag in the v filter. After prewhitening of the
main frequency (17.1438 c/d) the power spectrum does not show any further peak
with a global amplitude greater than 0.007

A tentative ephemeris is given as:

     HJD max. = 2447117.39742 + 0.05833d E
                         +/-8      +/-5

The general aspect of the light curves suggests that we are dealing with a Delta
Scuti type variable.

  A more detailed study of this star will be published later.




                            J.L. SEDANO
                            E. RODRIGUEZ
                            P. LOPEZ DE COCA

                      Instituto de Astrofisica de Andalucia
                        Apdo. 2144, Granada, Spain





Reference:
Ando, H. 1980, Astrophys. Space Sci. 71, 249. [BIBCODE 1980Ap&SS..71..249A ]