COMMISSION 27 OF THE I. A. U.
          INFORMATION BULLETIN ON VARIABLE STARS
                       Number 3003



                                       Konkoly Observatory
                                       Budapest
                                       23 March 1987

                                       HU ISSN 0374-0676


               53 PISCIUM - LARGER AMPLITUDE


  53 Psc (HR 155, HD 3379, BD+14d 76, AG Psc) is a bright star ordinarily
classified as B3V or B2.5IV. A light variation of this star was first 
announced by Williams (1954 a,b). He found the small amplitude of 0.02 
magnitude in yellow filter and derived a period of 0,09165 day. The short period
of light variation and the spectral type of this star suggested that it might
belong to the beta Canis Maioris star class.
  On the other hand, Percy (1971) concluded that 53 Psc is not a variable
star. Finally, J.-P. Sareyan et al. (1979) based on their photoeletric and
spectroscopic studies classified this star as a member of the beta CMa variable
star group. A small amplitude of 0,01 mag in UV filter and 0,002.-0,003
mag in blue filter with the period of 0,08 day was obtained. From one night
series of 11 spectra the radial-velocity in the range from -11 to -18 km/s
was measured and line variations were detected.
  In the year 1985 53 Psc was used as a zero point of comparison stars and
primary flux standard for International Halley Watch Photometry and Polarimetry
Net. A larger magnitude deviation of this star led to the independent 
photometric measurement. The 65 cm telescope of the Charles University 
at the Ondrejov Observatory was used. The comparison and check star
was 34 Psc (V=5.47. B8V) and 66 Psc (V=5.70, A1V), respectively. The result
of measurements in V colour of UBV system from October 3, 1985 is plotted
in Fig 1. One can obtain approximately the amplitude of 0,035 magnitude
and the period of 0,096 day. This significant change of the amplitude is
possible explained as an interference between two different periods.
   Further observations are required in order to confirm this amplitude
progress and to understand the light variations of this star.


                            [FIGURE 1]

 Figure 1. Light variations of 53 Psc in V colour. Standard error is 
 indicated.



                               MAREK WOLF
                Department of Astronomy and Astrophysics
                           Charles University
                   Svedska 8, 150 00 Praha 5, Czechoslovakia



References:

Percy, J.R., 1971, Astron. J., 76, 1105 [BIBCODE 1971AJ.....76.1105P ]
Sareyan, J.-P., Le Contel, J.-M., Ducatel, D. and Valtier, J.-C., 1979,
  Astron. Astrophys., 72, 313 [BIBCODE 1979A&A....72..313S ]
Williams, A.D., 1954 a, Publ. Astron. Soc. Pacific, 66, 25 [BIBCODE 1954PASP...66...25W ]
Williams, A.D., 1954 b, Publ. Astron. Soc. Pacific, 66, 88 [BIBCODE 1954PASP...66...88W ]