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arXiv · 2209.00270

The spin-up of a star gaining mass in a close binary system on the thermal time scale

Evgeny Staritsin
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Abstract

We investigate the exchange of mass in a binary system as a channel through which a Be star can receive a rapid rotation. The mass-transfer phase in a massive close binary system in the Hertzsprung-gap is accompanied by the spinning up of the accreting component. We consider a case when the mass of the accreting component increases by 1.5 times. The component acquires mass and angular momentum while in a state of critical rotation. The angular momentum of the component increases by 50 times. Meridional circulation effectively transports angular momentum inside the component during the mass-transfer phase and during the thermal time scale after the end of the mass-transfer phase. As a result of mass transfer, the component acquires the rotation typical of classical Be stars.

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Evgeny Staritsin. 2022-09-01. The spin-up of a star gaining mass in a close binary system on the thermal time scale. https://doi.org/10.1088/1674-4527/ac8f8d

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