GW Ori is a classical T Tauri star. Shevchenko et al. (1992, Inform.
Bull. Var. Stars N 3747) have discovered periodical decreasing of its
brightness, time interval between which was practically equal to the period
of radial velocity variations P ~ 242d found by Mathieu et al.
(1991, AJ v.101, p.2184). The duration of these dips d t ~ 0.1 P
was constant during 1988-1992 yrs, but their amplitude subsequently
decreased and they were not observe in 1994 and 1996 yrs seasons. We
assume that these events were due to an eclipse of the primary star by dust
and gas filling the Roche lobe of the companion. The envelope formed as a
result of an accretion event from the circubinary disc and then has
disappeared due to infall of the matter onto the companion. The parameters
of the system are estimated in the frame of this hypothesis.