The 1997/1998 eclipse of VV Cephei was late

The recent eclipse of the long-period (P = 7430(d)) binary star VV Cephei i s studied by means of UBV photometry and optical spectroscopy. Both photome try and variations of the emission lines (H alpha and Fell lambda 4233) sho w that the eclipse occured about 68 days later than predicted from the ephe meris. Such a sudden about 1% lengthening of the orbital period between the last two eclipses implies that the generally accepted model of VV Cep with the masses of both the M supergiant and the hot B star of about 20 M-circl e dot should be revised. The period change due to mass transfer between the components or mass ejection from the VV Cep system can be explained, if on e accepts the medium mass model for VV Cep, with the mass of the M star abo ut 2.5 M-circle dot and of the B star about 8 M-circle dot. This model impl ies that the cool component of VV Cep could be an AGE star rather than a su pergiant.