The Period Evolution of V473 Tau

TL;DR

This study investigates the period evolution of the chemically peculiar star V473 Tau using over fifty years of data, revealing a slight decrease in its rotation period likely caused by magnetic acceleration and differential rotation.

Contribution

First combined space-based and archival data to analyze V473 Tau's period evolution, revealing potential magnetic and differential rotation effects on its period change.

Findings

Rotation period is approximately 1.406829 days.

Period decreases at about 0.11 seconds per year.

Star's magnetic properties likely develop before or at the start of the main sequence.

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.