The Period Evolution of V473 Tau

Abstract

In this paper, the period evolution of the rotating chemically peculiar star V473\,Tau is investigated. Even though the star has been observed for more than fifty years, for the first time four consecutive years of space-based data covering between 2007 and 2010 are presented. The data are from the {\sl STEREO} satellite, and are combined with the archival results. The analysis shows that the rotation period of V473\,Tau is $1.406829(10)$ days, and has slightly decreased with the variation rate of 0.11(3)~s~yr${}^{-1}$ over time. Also, the acceleration timescale of the star is found to be shorter than its main sequence lifetime. This indicates that the process of decrease in period might be reversible. On this basis, it can be suggested that V473\,Tau has a possible magnetic acceleration and a differential rotation, which cause a variation in the movement of inertia, and hence the observed period change. Additionally, the evolution path of V473\,Tau on the H-R diagram is evaluated. Accordingly, the position of the star on the diagram suggests that its magnetic properties develop before it reaches the main sequence or in the beginning of its main sequence lifetime.

3 tables, 3 figures, 9 pages, The preliminary results arXiv:1702.00157 were published in AIP conference proceedings. The current study have been significantly improved in terms of the results and discussion part and also accepted by IBVS for publication