The Far Ultraviolet Light Curve of 78 Vir (A2p SrCrEu)

Abstract

Abstract All IUE spectra obtained shortwards of 2000 Å with the SWP camera are used to construct a far-ultraviolet (FUV) light curve at 1500 Å for 78 Vir over its rotational period. Setting an arbitrary phase 0.00 for the first spectrum recorded on 1987 May 10, the minimum and maximum occur respectively near phases 0.20–0.25 and 0.60–0.70. The Fine Error Sensor counts, which measure the brightness near the V band, vary in phase with the FUV flux, which is the opposite situation to that observed in another cool Ap star, 21 Com.