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arXiv 2102.08133astro-ph.EPastro-ph.SR
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南TESS 92颗候选行星的特征和冷矮星的新光度[Fe/H]关系

Characterisation of 92 Southern TESS Candidate Planet Hosts and a New Photometric [Fe/H] Relation for Cool Dwarfs

Adam D. Rains, Maruša Žerjal, Michael J. Ireland, Thomas Nordlander, Michael S. Bessell, Luca Casagrande, Christopher A. Onken, Meridith Joyce, Jens Kammerer, Harrison Abbot

摘要:

我们提出了一个中等分辨率的光学光谱调查的92冷($3,000 \lesssim T_{\rm eff} \lesssim 4,500\,$ K)南部TESS候选行星主机的结果,并描述了我们的光谱拟合方法用于恢复恒星参数。我们量化模型的不足之处,在预测光通量,虽然我们的技术工作良好的$T_{\rm eff}$,[Fe/H]需要进一步改进。为此,我们开发了一个更新的光度[Fe/H]校准孤立的主序星建立在校准样本的69个冷矮星的二元系统,精确到$\pm0.19\,$ dex,从超太阳的金属穷人,超过$1.51 < {\rm Gaia}~(B_P-R_P) < 3.3$。我们拟合的$T_{\rm eff}$和$R_\star$的中位精度分别为0.8%和1.7%,与我们的标准星样本一致。我们用这些来模拟凌日光变曲线,并确定100颗候选行星的系外行星半径,精度为3.5%,并看到行星半径差距也存在于冷矮星的证据。我们的结果与已确认的TESS行星样本一致,这项调查代表了迄今为止对冷TESS候选行星宿主最大的统一分析之一。

英文摘要:

We present the results of a medium resolution optical spectroscopic survey of 92 cool ($3,000 \lesssim T_{\rm eff} \lesssim 4,500\,$K) southern TESS candidate planet hosts, and describe our spectral fitting methodology used to recover stellar parameters. We quantify model deficiencies at predicting optical fluxes, and while our technique works well for $T_{\rm eff}$, further improvements are needed for [Fe/H]. To this end, we developed an updated photometric [Fe/H] calibration for isolated main sequence stars built upon a calibration sample of 69 cool dwarfs in binary systems, precise to $\pm0.19\,$dex, from super-solar to metal poor, over $1.51 < {\rm Gaia}~(B_P-R_P) < 3.3$. Our fitted $T_{\rm eff}$ and $R_\star$ have median precisions of 0.8% and 1.7%, respectively and are consistent with our sample of standard stars. We use these to model the transit light curves and determine exoplanet radii for 100 candidate planets to 3.5% precision and see evidence that the planet-radius gap is also present for cool dwarfs. Our results are consistent with the sample of confirmed TESS planets, with this survey representing one of the largest uniform analyses of cool TESS candidate planet hosts to date.

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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