Volume 45 number 1 (2017)
(Abstract only) We present time-series photometry of ES Ceti, a close binary with an orbital period of 10.3 minutes. The star is a member of the “AM CVn” class of cataclysmic variable, in which the two components are both white dwarfs, and the transferred matter is pure helium. Photometry during 2001–2016 shows that the orbital period is rapidly increasing, with P/(dP/dt) = 10 million years. This is consistent with the hypothesis that the mass transfer and binary evolution are driven by gravitational radiation, and appears to be the first such demonstration in any cataclysmic variable.