The photometric variability of the Be star NW Serpentis

Abstract

{NW Ser} is a bright (V = 6.1 - 6.2) active Be star which is known to vary photometrically on a time scale of hours to days. Using both Hipparcos and ground-based photometry, and using light curve, autocorrelation, power spectrum analysis and phase dispersion minimalization techniques, we have concluded that the period is close to 0.46d - a period typical of stars of this type, and in good agreement with the value of 0.488d, recently determined by Hubert & Floquet from Hipparcos data. It is possible that the period is near twice this value, but the evidence is not strong. We also find a period of about 5d. from both the ground-based and Hipparcos data.