Pulsating sdB Stars: A New Approach to Probing their Interiors

Abstract

Horizontal branch stars should show significant differential rotation with depth. Models that assume systematic angular momentum exchange in the convective envelope and local conservation of angular momentum in the core produce HB models that preserve a rapidly rotating core. A direct probe of core rotation is available. The nonradial pulsations of the EC14026 stars frequently show rich pulsation spectra. Thus their pulsations probe the internal rotation of these stars, and should show the effects of rapid rotation in their cores. Using models of sdB stars that include angular momentum evolution, we explore this possibility and show that some of the sdB pulsators may indeed have rapidly rotating cores.

arXiv comment8 pages, 3 figures; paper presented at Keele Workshop on Extreme Horizontal Branch Stars and Related Objects, June 2003 (ed. Pierre Maxsted)

References in corpus (8)

• The Origin of Extreme Horizontal Branch Stars
• Rotations and Abundances of Blue Horizontal-Branch Stars in Globular Cluster M15
• A New Spin on the Problem of HB Gaps: Stellar Rotation along the Blue Horizontal Branch of Globular Cluster M13
• Rotation of Horizontal Branch Stars in Globular Clusters
• On the Formation of Helium Double Degenerate Stars and Pre-Cataclysmic Variables
• Prospects for Measuring Differential Rotation in White Dwarfs Through Asteroseismology
• Rotation, Planets, and the "Second Parameter" of the Horizontal Branch
• Observations of the pulsating subdwarf B star Feige 48: Constraints on evolution and companions