Limits on Stellar and Planetary Companions in Microlensing Event OGLE-1998-BUL-14
Limits on Stellar and Planetary Companions in Microlensing Event OGLE-1998-BUL-14
复制标题
微透镜事件中恒星和行星伴星的限制 OGLE-1998-BUL-14
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
(The PLANET Collaboration)
中科院分区：
文献类型：
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作者：
M. Albrow;J. Beaulieu;J. Caldwell;D. Depoy;M. Dominik;B. Gaudi;A. Gould;J. Greenhill;K. Hill;S. Kane;R. Martin;J. Menzies;R. M. Naber;R. Pogge;K. Pollard;P. Sackett;K. Sahu;P. Vermaak;R. Watson;A. Williams;(The PLANET Collaboration)
我们展示了 OGLE-1998-BUL-14 的 PLANET 光度数据集，这是 1998 年 OGLE 合作对银河核球发出的高放大倍率 (Amax ~ 16) 事件警报。PLANET 数据集总共包含 461 个 I 波段点和 139 个 V 波段点，其中大部分是在 3 个月内拍摄的。此期间的中值采样间隔约为 1 小时，事件峰值的 1 σ 散布为 1.5%。该事件出色的数据质量和高最大放大倍率使其成为搜索短时低幅度扰动的主要候选对象，这些扰动是绕主透镜运行的行星伴星的特征。观察到的 OGLE-1998-BUL-14 光曲线在光度不确定度范围内与单透镜（无伴星）一致。我们计算光变曲线对透镜伴星的检测效率，作为两个组件的质量比和角距的函数。我们发现，对于 0.4 和 2.4rE 之间的投影间隔，质量比 ≥ 0.01 的伴星在 95% 显着性水平上被排除，其中 rE 是主透镜的爱因斯坦环半径。假设主星是一颗 rE ~ 3 AU 的 G 矮星，对于具有木星质量和分离度的伴星，我们对此事件的检测效率约为 60%，而对于具有土星质量和分离度的伴星，我们对此事件的检测效率约为 5%。我们对 υ 和 14 Her 周围行星的效率 > 75%。
We present the PLANET photometric data set for OGLE-1998-BUL-14, a high-magnification (Amax ~ 16) event alerted by the OGLE collaboration toward the Galactic bulge in 1998. The PLANET data set consists a total of 461 I-band and 139 V-band points, the majority of which was taken over a 3 month period. The median sampling interval during this period is about 1 hr, and the 1 σ scatter over the peak of the event is 1.5%. The excellent data quality and high maximum magnification of this event make it a prime candidate to search for the short-duration, low-amplitude perturbations that are signatures of a planetary companion orbiting the primary lens. The observed light curve for OGLE-1998-BUL-14 is consistent with a single lens (no companion) within photometric uncertainties. We calculate the detection efficiency of the light curve to lensing companions as a function of the mass ratio and angular separation of the two components. We find that companions of mass ratio ≥ 0.01 are ruled out at the 95% significance level for projected separations between 0.4 and 2.4rE, where rE is the Einstein ring radius of the primary lens. Assuming that the primary is a G dwarf with rE ~ 3 AU, our detection efficiency for this event is ~60% for a companion with the mass and separation of Jupiter and ~5% for a companion with the mass and separation of Saturn. Our efficiencies for planets like those around υ And and 14 Her are > 75%.