Astron. Astrophys. 331, 171-178 (1998)

4. Conclusions

In this work we have carried out a photometric study of the low amplitude  Sct star 20 CVn based on simultaneous uvby observations collected during the year 1995. Frequency analysis to our data together with the reanalysis of old photometric data sets suggest this star as a monoperiodic pulsator in which only the first harmonic is present. Intrinsic Strömgren values have been derived and the physical parameters of this star were determined and compared with those obtained by earlier authors. The analysis of the phase shifts and amplitude ratios between observed light and colour variations, using both uvby and UBV photometry, suggests radial pulsation in the fundamental mode or first overtone for 20 CVn. Nevertheless, taking into account the spectroscopic results from earlier authors, it would be very interesting to investigate the behaviour of this star with simultaneous spectroscopic and multicolor photometric observations.

In addition, the classical O-C method has been used in order to study the behaviour of the period suggesting that it is decreasing with time during the last three decades, but the value found for the period change is too large as compared with those observed for other  Sct stars. Revision of the different data sets available from bibliography does not reveal significant changes in the luminosity amplitude of this star from one session to another. However, in these last two aspects more observations are needed over the coming years to get more definitive conclusions.

© European Southern Observatory (ESO) 1998

Online publication: February 4, 1998
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