THE ORBIT AND COMPANIONS OF THE CLASSICAL CEPHEID FF-AQL

New radial velocities of the classical Cepheid FF Aql have been obtained and combined with previous observations to provide a revised orbit. A companion has been detected at 1800 Å in IUE spectra with a spectral type of A9 V to F3 V. If the Cepheid has an evolutionary mass, then the mass ratio is script M sign1/ script M sign2 = 3.8. A companion recently detected by speckle interferometry is in a longer-period orbit if it is a physical companion. In this case it is also an evolved star. The possible fourth member of the system, the visual companion, is unlikely to be a member of the system. The companion at 6″ is unlikely to be a physical companion. Cepheids (in the "free-fall" descending branch of the light curve) and nonvariable supergiants are shown to have a different spectral slope between 2900 and 1800 Å [for the same (B - V)0]. IUE spectra of Polaris are rediscussed using other Cepheid spectra as comparison stars, and it is concluded that there is probably no sign of a companion.