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arXiv 0803.4159astro-ph
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用高精度相对天体测量搜索太阳系外行星

Search for extrasolar planets with high-precision relative astrometry

T. Roell, A. Seifahrt, R. Neuhäuser

摘要:

我们提出了我们的搜索程序,使用高精度相对天文学的亚恒星同伴。由于它围绕恒星的轨道运动,一个看不见的亚恒星伴星会产生主恒星的周期性“摆动”,这是看不见的伴星的天体测量信号。通过测量双星系统和三星系统组成部分之间的距离,我们希望间接地测量一个可能看不见的伴星的天体测量信号,作为这些距离的相对和周期性变化。使用新的观察模式(“立方体模式”)其中帧直接保存在立方体中而在读出期间几乎没有时间损失,一个自适应光学系统来校正大气噪声,一个红外窄带滤波器在近红外线来抑制差分色折射(DCR)效应,我们实现了我们的第一个目标(双星HD 19994)的分离测量的相对精度约为100... 150微阿秒/时为了达到微弧秒制度的精度,我们使用统计方法。我们每个目标和历元取几千帧,并且在高斯分布的验证之后,测量精度可以计算为我们的测量的标准偏差除以高斯分布测量的数量的平方根。我们观测到的第一个目标是恒星双星HD 19994 A & B,其中A分量有一个已知的径向速度行星候选者。

英文摘要:

We present our search program for substellar companions using high-precision relative astronomy. Due to its orbital motion around the star, an unseen substellar companion would produce a periodic "wobble" of the host star, which is the astrometric signal of the unseen companion. By measuring the separation between the components of stellar double and triple systems, we want to measure this astrometric signal of a possible unseen companion indirectly as a relative and periodic change of these separations. Using a new observation mode (the "cube-mode") where the frames were directly saved in cubes with nearly no loss of time during the readout, an adaptive optics system to correct for atmospheric noise and an infrared narrow band filter in the near infrared to suppress differential chromatic refraction (DCR) effects we achive for our first target (the double star HD 19994) a relative precision for the separation measurements of about 100...150 micro-arsecond per epoch. To reach a precision in the micro-arcsec-regime, we use a statistical approach. We take several thousand frames per target and epoche and after a verification of a Gaussian distribution the measurement precision can be calculated as the standard deviation of our measurements divided by the square root of the number of Gaussian distributed measurements. Our first observed target is the stellar binary HD 19994 A & B, where the A component has a known radial velocity planet candidate.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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