V1334 Cygni: A Triple System Containing a Classical Cepheid

Abstract

We have observed the small-amplitude Cepheid V1334 Cyg A (pulsation period 3.3 days) for nearly 30 years. From these radial velocity data we have derived an orbit with a period of 5 years. From this orbit we have derived limits on the mass of the companion (V1334 Cyg C) of 3.1 to 4.4 M_solar. The system is also a marginally resolved visual binary with a much longer period that has been observed for nearly a century. We have used an IUE high-resolution spectrum to conclude that the hottest star in the system (V1334 Cyg B), which dominates the spectrum in the ultraviolet, is the wide companion, since the velocity is very near the systemic velocity.