arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2011.11821astro-ph.SRastro-ph.EP
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HD 139614的精确星震年龄和金属丰度:一颗在上半人马座狼疮中具有原行星盘的前主序星

A precise asteroseismic age and metallicity for HD 139614: a pre-main-sequence star with a protoplanetary disc in Upper-Centaurus Lupus

Simon J. Murphy, Meridith Joyce, Timothy R. Bedding, Timothy R. White, Mihkel Kama

摘要:

HD\,139614是一颗$\sim$,年龄约1400万年,可能是前主序星,位于Sco-Cen OB星协的上半人马座-狼座子群中,有一个轻微扭曲的周星盘,包含有环结构,暗示有一颗或多颗行星。除了挥发性元素外,这颗恒星的化学丰度模式是缺乏金属的,这使它处于$λ$ Boo类,并表明它最近吸积了富含气体但缺乏尘埃的物质。我们确定七个偶极和四个径向脉动模式之间的$δ$ Sct脉动使用TESS光变曲线和埃歇尔图。MESA恒星演化和GYRE恒星振荡程序的精确建模证实了它位于主序前。基于网格的天文地震模型表明,$10.75\pm0.77$ Myr的年龄为$1.52\pm0.02$ M $_{\odot}$,全球金属丰度为$Z=0.0100\pm0.0010$。这是第一次通过星震测定$λ$ Boo星的金属丰度。精确的年龄和金属丰度为上半人马座-狼疮的年龄估计提供了基准,并为了解中等质量恒星周围的圆盘保留和行星形成提供了基准。

英文摘要:

HD\,139614 is known to be a $\sim$14-Myr-old, possibly pre-main-sequence star in the Sco-Cen OB association in the Upper Centaurus-Lupus subgroup, with a slightly warped circumstellar disc containing ring structures hinting at one or more planets. The star's chemical abundance pattern is metal-deficient except for volatile elements, which places it in the $λ$ Boo class and suggests it has recently accreted gas-rich but dust-poor material. We identify seven dipole and four radial pulsation modes among its $δ$ Sct pulsations using the TESS light curve and an échelle diagram. Precision modelling with the MESA stellar evolution and GYRE stellar oscillation programs confirms it is on the pre-main sequence. Asteroseismic, grid-based modelling suggests an age of $10.75\pm0.77$ Myr, a mass of $1.52\pm0.02$ M$_{\odot}$, and a global metal abundance of $Z=0.0100\pm0.0010$. This represents the first asteroseismic determination of the bulk metallicity of a $λ$ Boo star. The precise age and metallicity offer a benchmark for age estimates in Upper Centaurus--Lupus, and for understanding disc retention and planet formation around intermediate-mass stars.

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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