Towards comprehension of the variability of the magnetic chemically peculiar star CU Virginis (HD 124224)

TL;DR

This paper investigates the complex variability of CU Virginis, a magnetic chemically peculiar star, by analyzing 53 years of multi-source photometric and spectroscopic data to model its secular rotational period oscillations.

Contribution

It introduces a phenomenological approach to model long-term period variations of CU Virginis using a fifth degree polynomial based on extensive observational data.

Findings

Secular period variations are well fitted by a fifth degree polynomial.

The star exhibits strictly periodic light variations across the electromagnetic spectrum.

The analysis enhances understanding of the star's rotational behavior over 53 years.

Abstract

The upper main sequence stars CU Virginis is the most enigmatic object among magnetic chemically peculiar (mCP) stars. It is an unusually fast rotator showing strictly periodic light variations in all regions of the electromagnetic spectrum, as well as spectroscopic and spectropolarimetric changes. At same time, it is also the first radio main-sequence pulsar. Exploiting information hidden in phase variations, we monitored the secular oscillation of the rotational period during the last 53 years. Applying own phenomenological approach, we analyzed 37\,975 individual photometric and spectroscopic measurements from 72 data sources and improved the O-C model. All the relevant observations indicate that the secular period variations can be well approximated by the fifth degree polynomial.