A Search for Hot Massive Extrasolar Planets around Nearby Young Stars with the Adaptive Optics System NACO
A Search for Hot Massive Extrasolar Planets around Nearby Young Stars with the Adaptive Optics System NACO
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使用自适应光学系统 NACO 搜索附近年轻恒星周围的热大质量太阳系外行星
DOI：
10.1086/429687
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发表时间：
2005
期刊：
影响因子：
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通讯作者：
Laboratorio de Astrofisica Espacial y Fisica Fundamental
中科院分区：
文献类型：
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作者：
E. Masciadri;R. Mundt;T. Henning;C. Álvarez;D. B. Y. N. M. I. F. Astronomie;Laboratorio de Astrofisica Espacial y Fisica Fundamental
我们报道了一项由 NACO 在 VLT 进行的调查，该调查致力于寻找年轻恒星和邻近恒星周围的系外行星。给出了 28 个最佳可用目标与恒星角距的检测极限。我们的调查中未检测到任何行星质量伴星，首次用于推导预计的行星与恒星分离的上限频率。特别是，我们发现在 50% 的情况下，在预计距离大于 14 个天文单位时没有检测到 5MJ（或更大质量）的行星，在预计距离大于 8.5 个天文单位时也没有检测到 10MJ（或更大质量）的行星。在 100% 的情况下，这些值分别增加到 36 和 65 AU。与之前的研究相比，我们的研究达到了出色的灵敏度，使得预计的行星-恒星分离的上限要低得多。例如，对于 β Pictoris 群（~12 Myr），我们没有在距离大于 15 个天文单位的地方检测到任何 10MJ 的行星。之前使用 4 m 级望远镜进行的一项研究将 10MJ 行星的上限设定为约 60 个天文单位。对于我们最近的目标（V2306 Oph；d = 4.3 pc），结果表明，可以在与恒星的最小预计距离为 1 个天文单位的情况下探测到一颗 10MJ 的行星，在与恒星的最小预计距离为 3.7 个天文单位的情况下探测到 5MJ 的行星。我们的研究结果涉及解释行星形成和迁移的机制以及即将推出的观测策略和未来的行星探测器地面观测。
We report on a survey devoted to the search of exoplanets around young and nearby stars carried out with NACO at the VLT. The detection limit for 28 among the best available targets versus the angular separation from the star is presented. The nondetection of any planetary mass companion in our survey is used to derive, for the first time, the frequency of the upper limit of the projected planet-star separation. In particular, we find that in 50% of the cases, no 5MJ (or more massive) planet has been detected at projected separations larger than 14 AU, and no 10MJ (or more massive) planet has been detected at projected separations larger than 8.5 AU. In 100% of the cases, these values increase to 36 and 65 AU, respectively. The excellent sensitivity reached by our study leads to a much lower upper limit of the projected planet-star separation compared with previous studies. For example, for the β Pictoris group (~12 Myr), we did not detect any 10MJ planet at distances larger than 15 AU. A previous study carried out with 4 m class telescopes put an upper limit for 10MJ planets at ~60 AU. For our closest target (V2306 Oph; d = 4.3 pc), it is shown that it would be possible to detect a 10MJ planet at a minimum projected separation from the star of 1 AU and a 5MJ planet at a minimum projected separation of 3.7 AU. Our results are discussed with respect to mechanisms explaining planet formation and migration and forthcoming observational strategies and future planet-finder observations from the ground.