PROPERTIES AND NATURE OF BE STARS .17. V360 LAC=HD-216200 IS A B3E+F9IV BINARY

An analysis of an extensive collection of photometric and spectroscopi c observations of the little studied bright Be star V360 Lac lead to t he following main conclusions: (1) V360 Lac is a binary system consist ing of a B3e primary and a F9IV secondary which probably fills the Roc he lobe and losses mass towards the primary. Radial-velocity curves of both components were obtained. (2) The light variations arise from su perposition of variations on at least three time scales: phase-locked orbital bright ness and colour changes with two minima; sinusoidal var iation with a 322.(d)24 period and low-amplitude rapid changes with a possible period of 1.(d)6738. (3) A tentative solution of the B and V light curves which assumes the semi-detached configuration and presenc e of a disk around the primary, combined with the orbital solution, le ads to preliminary basic physical elements of the system which are con sistent with the radiative properties of the binary components.