engleski

The nerarby ellipsoidal variable TV Pictoris

TV Pic is identified as a bright, near-contact mid-A+early-F binary seen under a moderate inclination of 54 deg. From the analyses reported in this paper, it appears that both components are undermassive (1.2+0.4 Msun), and that the secondary rotates not synchronously but more than twice as fast. These conclusions follow from the analysis of (1) high-dispersion spectra near both quadrature phases, to which the secondary contributes roughly 10% in the visual light, and (2) light-curves in the Stroemgren and Walraven system covering the interval 3200-5600 A and a time span of more than 2600 rotational periods. The light-curves show a very pronounced OConnell effect, and only marginal colour variations. Models assuming a temperature spot either on the primary or the secondary explain the major part of the asymmetry in the light-curves, and are intended to provide useful initial estimates for more advanced mathematical codes. However, a more realistic physical model will require more discriminatory data, including spectroscopic observations in other spectral windows, and spectroscopy over the whole orbital cycle.

close binaries; variable stars; HD 30861 (TV Pic); fundamental parameters; rotation

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