New Determinations of the Rotational Periods of 78 Vir (A2p SrCrEu) and 52 Her (A1p SiSrCr)

Abstract

Abstract The TESS lightcurves of the two cool Ap stars, 78 Vir and 52 Her, are used to derive new rotational periods for both stars. A frequency analysis of the light curve of 52 Her with the Generalized Lomb–Scargle periodogram reveals a periodic structure with three harmonics. The inverse of the fundamental frequency yields a rotational period of 3.840 ± 0.037 days for 52 Her. The same analysis for 78 Vir yields two harmonics with a rotation period of 3.718 ± 0.037 days, only slightly shorter than previous determinations.