Photometry of the intermediate polar TV Columbae

Abstract

Thirty-seven hours of high-speed photometry of TV Col, spread over a three-week baseline, are analyzed for periodicities. The previously known 5.2 hr, 5.5 hr and 4.0 day periods are confirmed; mean light curves at those periods are presented. There is no sign in our optical observations of the 1911 s X-ray period reported by Schrijver, Brinkman & van der Woerd. An extension of the freely precessing disc model of Bonnet-Bidaud, Motch & Mouchet is proposed to explain the occurrence of the multiple periods. We suggest that the disc is maintained in a tilted position with respect to the orbital plane by being fed by material controlled by the magnetic field of the secondary. A surface field ≃200 G appears to be adequate to supply such guided material.