PRECISE RADIAL VELOCITY MEASUREMENTS FOR KEPLER GIANTS HOSTING PLANETARY CANDIDATES: KEPLER-91 AND KOI-1894
PRECISE RADIAL VELOCITY MEASUREMENTS FOR KEPLER GIANTS HOSTING PLANETARY CANDIDATES: KEPLER-91 AND KOI-1894
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DOI：
10.1088/0004-637x/802/1/57
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发表时间：
2015-01
期刊：
影响因子：
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通讯作者：
B. Sato;T. Hirano;M. Omiya;H. Harakawa;Atsushi Kobayashi;Ryo Hasegawa;T. Takarada;K. Kawauchi;K. Masuda
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文献类型：
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作者：
B. Sato;T. Hirano;M. Omiya;H. Harakawa;Atsushi Kobayashi;Ryo Hasegawa;T. Takarada;K. Kawauchi;K. Masuda
我们目前的径向速度后续观测的两个开普勒演化恒星开普勒-91（KOI-2133）和KOI-1894，这已被宣布为候选人的主机过境巨行星，与斯巴鲁8.2米望远镜和高色散光谱仪（HDS）的结果。通过对Subaru/HDS获得的高精度径向速度数据和开普勒使命获得的光度数据进行全球建模，以解释轨道亮度调制（椭球变化，反射/发射光等）。我们独立地证实开普勒-91拥有一颗质量为0.66 M Jup的凌日行星。（开普勒-91 b），并在2001年的时间间隔上新发现了200 m s−1的径向速度偏差，表明系统中存在额外的伴星。KOI-1894的视向速度和光变曲线可能存在相位变化，置信度为2-3σ，这可以解释为星星的反射运动和椭球变化是由一个次土星质量（约0.18 M Jup？>）行星。
We present results of radial-velocity follow-up observations for the two Kepler evolved stars Kepler-91 (KOI-2133) and KOI-1894, which had been announced as candidates to host transiting giant planets, with the Subaru 8.2 m telescope and the High Dispersion Spectrograph (HDS). By global modeling of the high-precision radial-velocity data taken with Subaru/HDS and photometric data taken by the Kepler mission accounting for orbital brightness modulations (ellipsoidal variations, reflected/emitted light, etc.) of the host stars, we independently confirmed that Kepler-91 hosts a transiting planet with a mass of 0.66 M Jup ?> (Kepler-91b), and newly detected an offset of ∼20 m s−1 between the radial velocities taken at ∼1 yr interval, suggesting the existence of an additional companion in the system. As for KOI-1894, we detected possible phased variations in the radial velocities and light curves with 2–3σ confidence level, which could be explained as a reflex motion and ellipsoidal variation of the star caused by a transiting sub-Saturn-mass (∼0.18 M Jup ?> ) planet.