Photometric orbital modulation in V 1080 Tauri

Abstract

We present a photometric study of the variable star V 1080 Tauri. All photometric data, spanning in total about 9 years, can be folded with the period of 8.8451741 days, yielding a single-wave course with the full amplitude of 0.14 mag. The Hipparcos data show that the secular trend in the brightness variations is not larger than 0.04 mag and that the modulation persists for the whole covered interval. We modeled the light curve by ellipsoidal variations because the spectroscopic analysis of Martín (1993) proved V 1080 Tau to be a close binary. We argue that the true orbital period is 17.69348 days, giving a double-wave light curve which can be attributed to the proximity effects in the semi-detached Algol binary. The absence of eclipses and the relatively large amplitude suggest the inclination angle within 55^̂ - 69^̂. The deviations from the ellipsoidal modulation, mainly near the phases 0.25 and 0.5, are interpreted in terms of interaction in the binary.