A posteriori detection of the planetary transit of HD 189733 b in the Hipparcos photometry
A posteriori detection of the planetary transit of HD 189733 b in the Hipparcos photometry
复制标题
依巴谷光度测量中 HD 189733 b 行星凌日的后验检测
DOI：
10.1051/0004-6361:20054308
复制
发表时间：
2005
影响因子：
6.5
通讯作者：
Guillaume HebrardAlain Lecavelier des Etangs
中科院分区：
文献类型：
--
作者：
Guillaume HebrardAlain Lecavelier des Etangs
目标。利用上普罗旺斯天文台进行的观测，最近报告发现了一颗轨道周期为2.2天的太阳系外行星，该行星穿过其母星星HD 189733的盘面。我们在依巴谷测光表中寻找可能探测到的凌日现象。方法.对依巴谷数据进行了统计学研究，以检测HD 189733 B的过境并量化其检测的显著性。结果高水平的信心，我们发现，依巴谷可能观察到一个过境HD 189733 B在1991年10月，并可能在1991年2月和1993年2月的其他两个。使用HD 189733 B可能周期的范围，我们发现这些事件都不是由于行星凌日，而是由于人工制品的概率低于0.15%。利用现有的15年时间基线，我们可以特别高精度地测量行星HD 189733 B的轨道周期。我们得到的周期为2.218574 +0.000006 -0.000010天，对应的精度为0.01秒。这种精确的测量可能会为同伴的存在提供线索。
Aims. Using observations performed at the Haute-Provence Observatory, the detection of a 2.2-day orbital period extra-solar planet that transits the disk of its parent star, HD 189733, has been recently reported. We searched in the Hipparcos photometry Catalogue for possible detections of those transits. Methods. Statistic studies were performed on the Hipparcos data in order to detect transits of HD 189733 b and to quantify the significance of their detection. Results. With a high level of confidence we find that Hipparcos likely observed one transit of HD 189733 b in October 1991, and possibly two others in February 1991 and February 1993. Using the range of possible periods for HD 189733 b, we find that the probability that none of those events are due to planetary transits but are instead all due to artifacts is lower than 0.15%. Using the 15-year temporal baseline available, we can measure the orbital period of the planet HD 189733 b with particularly high accuracy. We obtain a period of 2.218574 +0.000006 -0.000010 days, corresponding to an accuracy of ∼1 s. Such accurate measurements might provide clues for the presence of companions.