Modelling the photometric variability of magnetic massive stars with the Analytical Dynamical Magnetosphere model

Munoz, M. S.; Wade, G. A.; Naze, Y.; Puls, J.; Bagnulo, S. und Szymanski, M. K. (2020): Modelling the photometric variability of magnetic massive stars with the Analytical Dynamical Magnetosphere model. In: Monthly Notices of the Royal Astronomical Society, Bd. 492, Nr. 1: S. 1199-1213

Abstract

In this paper, we investigate the photometric variability of magnetic O-type stars. Such stars possess oblique, predominantly dipolar magnetic fields that confine their winds roughly axisymmetrically about the magnetic equator, thus forming a magnetosphere. We interpret their photometric variability as phase-dependent magnetospheric occultations. For massive star winds dominated by electron scattering opacity in the optical and NIR, we can compute synthetic light curves from simply knowing the magnetosphere's mass density distribution. We exploit the newly developed Analytical Dynamical Magnetosphere (ADM) model in order to obtain the predicted circumstellar density structures of magnetic O-type stars. The simplicity in our light-curve synthesis model allows us to readily conduct a parameter space study. For validation purposes, we first apply our algorithm to HD 191612, the prototypical Of?p star. Next, we attempt to model the photometric variability of the Of?p-type stars identified in the Magellanic Clouds using OGLE photometry. We evaluate the compatibility of the ADM predictions with the observed photometric variations and discuss the magnetic field properties that are implied by our modelling.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Physik
• Themengebiete: 500 Naturwissenschaften und Mathematik > 530 Physik
• ISSN: 0035-8711
• Sprache: Englisch