Exploring the photometric signatures of magnetospheres around Helium-strong stars

TL;DR

This study models the photometric signatures of magnetospheres in He-strong stars using the RRM model, revealing how light curve shapes depend on viewing angles and magnetic properties, aiding in constraining stellar parameters.

Contribution

It applies the RRM model to He-strong stars to link light curve morphology with magnetic and geometric parameters, providing a new method for stellar characterization.

Findings

Double-minimum light curves occur at high obliquity and inclination.

No light variations are observed at low obliquity and inclination.

Single-minimum light curves are typical at intermediate angles.

Abstract

The photometric variations due to magnetically confined material around He-strong stars are investigated within the framework of the Rigidly Rotating Magnetosphere (RRM) model. For dipole field topologies, the model is used to explore how the morphology of light curves evolves in response to changes to the observer inclination, magnetic obliquity, rotation rate and optical depth. The general result is that double-minimum light curves arise when the obliquity and/or inclination are close to 90 degrees; no light variations are seen in the opposite limit; and for intermediate cases, single-minimum light curves occur. These findings are interpreted with the aid of a simple, analytical torus model, paving the way for the development of new photometric-based constraints on the fundamental parameters of He-strong stars. Illustrative applications to five stars in the class are presented.