Adaptive Optics Observations of Vega: Eight Detected Sources and Upper Limits to Planetary-Mass Companions
Adaptive Optics Observations of Vega: Eight Detected Sources and Upper Limits to Planetary-Mass Companions
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织女星的自适应光学观测：八个检测到的源和行星质量伴星的上限
DOI：
10.1086/344750
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发表时间：
2002
期刊：
影响因子：
--
通讯作者：
R. White
中科院分区：
文献类型：
--
作者：
S. Metchev;L. Hillenbrand;R. White
根据 Palomar 5 m 望远镜的自适应光学观测，我们对距离织女星约 30 到 230 天文单位之间的任何行星伴星的质量设定了上限，其中我们的数据对比织女星本身更暗的 H = 12.5-19.0 mag 的深度敏感。我们的观测覆盖了一个由两个 25” × 57” 单元组成的加号区域，不包括以恒星为中心的 7” × 7” 单元。我们已经确定了两个双点源和四个单点源。这些预计的伴星比织女星暗 14.9-18.9 星等，如果物理上关联的话，质量将在 4 到 35 MJ 之间，轨道半径为 170-260 天文单位。最近对织女星周围尘埃环的模拟预测存在一个质量小于 2-3 MJ、轨道半径约为 40-100 AU 的摄动体，并且不能排除质量更大（≲10 MJ）的行星。检测到的物体都不是这个预测的行星。基于颜色幅度、光谱和自行分析，所有物体都与背景源一致。考虑到织女星的眩光，在我们的数据中，在 5 σ 水平上，接近预期轨道半径的 2 MJ 物体是看不到的，尽管任何质量大于 10 MJ 的褐矮星都可以在大于 80 AU 的间隔处看到。
From adaptive optics observations with the Palomar 5 m telescope we place upper limits on the masses of any planetary companions located between ~30 and 230 AU away from Vega, where our data are sensitive to depths ranging from H = 12.5-19.0 mag fainter than Vega itself. Our observations cover a plus-shaped area with two 25′′ × 57′′ elements, excluding 7′′ × 7′′ centered on the star. We have identified two double and four single point sources. These projected companions are 14.9-18.9 mag fainter than Vega and, if physically associated, would have masses ranging from 4 to 35 MJ and orbital radii of 170-260 AU. Recent simulations of dusty rings around Vega predict the presence of a perturbing body with a mass of less than 2-3 MJ and an orbital radius of ~40-100 AU, and more massive (≲10 MJ) planets cannot be excluded. None of the detected objects are this predicted planet. Based on a color-magnitude, spectroscopic, and proper motion analysis, all objects are consistent with being background sources. Given the glare of Vega, a 2 MJ object near the expected orbital radii would not have been visible at the 5 σ level in our data, though any brown dwarf with mass greater than 10 MJ could have been seen at a separation greater than 80 AU.