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arXiv 1902.07545astro-ph.SR
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类太阳恒星的弹弓日珥演化

Slingshot prominence evolution for a solar-like star

Carolina Villarreal D'Angelo, Moira Jardine, Colin P. Johnstone, Victor See

摘要:

虽然现在的太阳旋转得太慢,无法表现出离心力支持的“弹弓效应”,但在过去的某个时候,它可能已经形成了这些冷气体云,并将它们喷射到行星际介质中。我们确定这种行为的时间周期,通过使用旋转演化代码来推导出的弹弓的形成和弹射的性质,在生命周期的恒星类似于我们的太阳。利用我们以前工作中导出的解析表达式计算了这些双折射的质量、质量损失率和喷射率。我们发现,对于恒星的初始旋转速率大于$4.6\, Ω_\odot$,约一半的太阳质量的恒星,弹弓双折射将存在,即使在恒星达到主序星阶段。在快速自转的恒星中,这意味着直到恒星达到$\sim 800$ Myr年龄,才能形成双折射。我们的结果还表明,这种类型的突出物的质量和寿命有最大值时,恒星达到ZAMS在年龄为$\sim 40$ Myr的太阳质量的恒星。

英文摘要:

Although the present-day Sun rotates too slowly to exhibit centrifugally-supported 'slingshot prominences', at some time during its past it may have formed these clouds of cool gas and ejected them into the interplanetary medium. We determine the time period for this behaviour by using a rotation evolution code to derive the properties of the formation and ejection of slingshot prominences during the lifetime of a star similar to our Sun. The mass, mass loss rate and rate of ejection of these prominences are calculated using the analytical expression derived in our previous work. We find that for stars with an initial rotation rate larger than $4.6\, Ω_\odot$, about half of all solar mass stars, slingshot prominences will be present even after the star reaches the main sequence phase. In a fast rotator, this means that prominences can form until the star reaches $\sim 800$ Myr old. Our results also indicate that the mass and lifetime of this type of prominence have maximum values when the star reaches the ZAMS at an age of $\sim 40$ Myr for a solar mass star.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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