Observational Limits on Terrestrial-sized Inner Planets around the CM Draconis System Using the Photometric Transit Method with a Matched-Filter Algorithm
Observational Limits on Terrestrial-sized Inner Planets around the CM Draconis System Using the Photometric Transit Method with a Matched-Filter Algorithm
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使用匹配滤波器算法的光度凌日法对 CM Draconis 系统周围类地大小的内行星的观测限制
DOI：
10.1086/308830
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发表时间：
2000
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影响因子：
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通讯作者：
Efthimious Paleologou
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文献类型：
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作者：
L. Doyle;H. Deeg;Valerij P. Kozhevnikov;B. Oetiker;E. Martín;J. Blue;L. Rottler;Remington P. S. Stone;Z. Ninkov;J. Jenkins;J. Schneider;E. Dunham;M. Doyle;Efthimious Paleologou
分析了食双星CM Draconis的光变曲线，发现其存在大小≥ 2.5地球半径（RE）、周期小于等于60天、共面轨道的行星凌日现象。大约有4亿个模型光变曲线，代表了从7到60天周期的行星过境，已经与这些数据相匹配/相关。这个过程我们称之为“过境检测算法”或TDA。每个行星候选者的“过境统计数据”可以量化检测概率和误报率。我们目前的CM Dra光变曲线覆盖了1014小时，有26，043个单独的点，光度精度在0.2%到0.7%之间。比3RE大得多的行星将构成“超噪声”探测，在60天或更短的时间内，它们被探测到的概率将超过90%。对较小行星的“亚噪音”检测受到更多限制。例如，周期为10天或更短的2.5RE行星将以80%的概率被探测到。预测观测的必要性用我们的TDA分析中出现的九颗顶级行星候选者来说明。它们是1994-1998年观测季节凌日统计数字最高的候选行星，并预测它们将在1999年观测季节凌日。在1999年进行观测测试的七个候选者中，除了一个需要进一步观测确认之外，其他都被排除了。我们的结论是，测光过境方法是一种可行的方式来寻找相对较小的，内太阳系外行星与中等大小的望远镜使用CCD测光匹配过滤器分析。
A light curve of the eclipsing binary CM Draconis has been analyzed for the presence of transits of planets of size ≥ 2.5 Earth radii (RE), with periods of 60 days or less, and in coplanar orbits around the binary system. About 400 million model light curves, representing transits from planets with periods ranging from 7 to 60 days, have been matched/correlated against these data. This process we call the "transit detection algorithm" or TDA. The resulting "transit statistics" for each planet candidate allow the quantification of detection probabilities, and of false-alarm rates. Our current light curve of CM Dra has a coverage of 1014 hr with 26,043 individual points, at a photometric precision between 0.2% and 0.7%. Planets significantly larger than 3RE would constitute a "supranoise" detection, and for periods of 60 days or less, they would have been detected with a probability greater than 90%. "Subnoise" detections of smaller planets are more constrained. For example, 2.5RE planets with 10 day periods or less would have been detected with an 80% probability. The necessity for predicted observations is illustrated with the nine top planet candidates that emerged from our TDA analysis. They are the planet candidates with the highest transit statistics from the 1994-1998 observing seasons, and for them transits for the 1999 observing season were predicted. Of the seven candidates that were then observationally tested in 1999, all were ruled out except one, which needs further observational confirmation. We conclude that the photometric transit method is a viable way to search for relatively small, inner extrasolar planets with moderate-sized telescopes using CCD photometry with a matching-filter analysis.