出版社：SISSA, Scuola Internazionale Superiore di Studi Avanzati
摘要：We present fast timing photometric observations of the intermediate polar V2069 Cygni (RX J2123.7+4217) using the Optical Timing Analyzer (OPTIMA) at the Skinakas Observatory 1.3 m telescope. OPTIMA is a single-photon counting aperture photo-polarimeter with the timing accuracy of about 4 microseconds and absolute (GPS) tagging of photon arrival-times. The optical (450-950 nm) light curve of V2069 Cygni was measured with sub-second resolution during July 2009 and revealed a double-peaked pulsation with 743.385 (±0.250) s period. A similar doublepeaked modulation was found in simultaneous soft X-ray observations with the Swift satellite. We suggest that the 743.385 (±0.250) s period represents the spin of the white dwarf accretor. In the Porb-Pspin diagram of all IPs, V2069 Cyg is rather an indistinct member of this population. It has however a rather low spin to orbit ratio of 0.027.
