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arXiv 2204.04700astro-ph.SRastro-ph.EP
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TESS南连续视带近场M矮星的活动和自转

Activity and Rotation of Nearby Field M Dwarfs in the TESS Southern Continuous Viewing Zone

Francys Anthony, Alejandro Núñez, Marcel A. Agüeros, Jason L. Curtis, J. -D. do Nascimento,, João M. Machado, Andrew W. Mann, Elisabeth R. Newton, Rayna Rampall… 展开作者

Francys Anthony, Alejandro Núñez, Marcel A. Agüeros, Jason L. Curtis, J. -D. do Nascimento,, João M. Machado, Andrew W. Mann, Elisabeth R. Newton, Rayna Rampalli, Pa Chia Thao, Mackenna L. Wood

摘要:

晚型矮星的磁性演化仍然模糊不清,因为我们只能微弱地预测给定质量和年龄的M矮星的活动水平。我们报告的结果,从我们的光谱调查的M矮星在南部连续观察区(CVZ)的凌日系外行星调查卫星(TESS)。由于TESS CVZ与詹姆斯韦伯太空望远镜的CVZ重叠,我们的目标构成了附近M矮星研究的遗留样本。对于122颗恒星,我们获得了至少一个$R\approx 2000$光谱,我们测量色球$\mathrm{H}α$发射,磁场强度的代理。活跃恒星的比例与场M矮星的预期是一致的;正如在以前的研究中,我们发现晚型M矮星保持活跃的时间比早型M矮星要长。虽然我们的目标的$\approx$ 20%的TESS光变曲线显示调制与旋转一致,TESS系统学没有足够好的理解,以确保测量旋转周期($P_{\mathrm{rot}}$)长于观测扇区长度的一半。我们报告了12颗恒星的周期,我们测量了$P_{\mathrm{rot}} {\lower0.8ex\hbox{$ \buildrel < \over \sim $}}$ 15 d,或者在文献中找到了TESS导出的$P_{\mathrm{rot}}$的确认。我们的样本21 $P_{\mathrm{rot}}$,其中包括从文献中的周期,是一致的,我们的目标是自旋下降场星。最后,我们检查了我们的样品的$\mathrm{H}α$ -热光度分布。两颗恒星的旋转速度快到足以达到磁饱和,但不是,这暗示了快速旋转体可能在$\mathrm{H}α$中不活跃的可能性。

英文摘要:

The evolution of magnetism in late-type dwarfs remains murky, as we can only weakly predict levels of activity for M dwarfs of a given mass and age. We report results from our spectroscopic survey of M dwarfs in the Southern Continuous Viewing Zone (CVZ) of the Transiting Exoplanet Survey Satellite (TESS). As the TESS CVZs overlap with those of the James Webb Space Telescope, our targets constitute a legacy sample for studies of nearby M dwarfs. For 122 stars, we obtained at least one $R\approx 2000$ optical spectrum with which we measure chromospheric $\mathrm{H}α$ emission, a proxy for magnetic field strength. The fraction of active stars is consistent with what is expected for field M dwarfs; as in previous studies, we find that late-type M dwarfs remain active for longer than their early type counterparts. While the TESS light curves for $\approx$20% of our targets show modulations consistent with rotation, TESS systematics are not well enough understood for confident measurements of rotation periods ($P_{\mathrm{rot}}$) longer than half the length of an observing sector. We report periods for 12 stars for which we measure $P_{\mathrm{rot}} {\lower0.8ex\hbox{$\buildrel <\over\sim$}}$ 15 d or find confirmation for the TESS-derived $P_{\mathrm{rot}}$ in the literature. Our sample of 21 $P_{\mathrm{rot}}$, which includes periods from the literature, is consistent with our targets being spun-down field stars. Finally, we examine the $\mathrm{H}α$-to-bolometric luminosity distribution for our sample. Two stars are rotating fast enough to be magnetically saturated, but are not, hinting at the possibility that fast rotators may appear inactive in $\mathrm{H}α$.

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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