A cyclical period variation detected in the updated orbital period analysis of TV Columbae

Z. DAI; S.-B. QIAN; E. FERNÁNDEZ-LAJÚS; G. BAUME

ASTROPHYSICS AND SPACE SCIENCE

SPRINGER

Lugar: Dordrecht, The Netherlands; Año: 2010 vol. 330 p. 243 - 248

0004-640X

The two CCD photometries of the intermediate polar TV Columbae are made forobtaining the two updated eclipse timings with high precision. There is an intervaltime ~17yr since the last mid-eclipse time observed in 1991. Thus, the new mid-eclipse times can offer an opportunity to check the previous orbital ephemerides. Acalculation indicates that the orbital ephemeris derived by Augusteijn et al. (1994)should be corrected. Based on the proper linear ephemeris (Hellier 1993), the neworbital period analysis suggests a cyclical period variation in the O-C diagram of TVColumbae. Using Applegate´s  mechanism to explain the periodic oscillation in O-C diagram, the required energy is larger than that a M0-type star can afford over acomplete variation period ~31.0(±3.0)yr. Thus, the light travel-time effect indicates that the tertiary component in TV Columbae may be a dwarf with a low mass, which is near the mass lower limit ~0.08Mo as long as the inclination of the third body high enough.