EXPRES. I. HD 3651 as an Ideal RV Benchmark
EXPRES. I. HD 3651 as an Ideal RV Benchmark
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DOI：
10.3847/1538-3881/ab99c9
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发表时间：
2020-06
期刊：
影响因子：
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通讯作者：
J. Brewer;D. Fischer;R. Blackman;S. Cabot;A. Davis;G. Laughlin;C. Leet;J. Ong;R. R. Petersburg-R.;A. Szymkowiak;Lily L. Zhao;G. Henry;J. Llama
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文献类型：
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作者：
J. Brewer;D. Fischer;R. Blackman;S. Cabot;A. Davis;G. Laughlin;C. Leet;J. Ong;R. R. Petersburg-R.;A. Szymkowiak;Lily L. Zhao;G. Henry;J. Llama
下一代系外行星搜索光谱仪的径向速度(RV)精度应该比标准的1台最先进的光谱仪高出一个数量级。这一进展对于能够探测到类太阳恒星周围有地球质量的行星至关重要。新的校准技术，如激光频率梳和稳定标准具，确保了仪器稳定性的良好特性。然而，其他误差来源包括恒星噪声、未检测到的短周期行星和大地污染。为了了解并最终减少误差源，必须最大限度地隔离误差预算中的贡献条款。在这里，我们介绍一个新的高节奏RV计划，极端精密光谱仪(Expres)100地球调查，旨在识别明亮的附近G和K矮星周围的岩石行星。我们还提供了一个基准案例：一颗土星质量的行星绕着色球安静的恒星HD 3651运行62天的轨道。高偏心率(0.6)和中等长的轨道周期相结合，确保了任何内行星的显著动力学清理。我们对这个行星轨道的开普勒式模型在−6个月的时间基线上的残差均方根为58厘米S∼1。通过消除对房车误差预算有重大贡献的因素，HD 3651可作为评估极高精度房车计划长期精度的标准。
The next generation of exoplanet-hunting spectrographs should deliver up to an order of magnitude improvement in radial velocity (RV) precision over the standard 1 state-of-the-art spectrographs. This advance is critical for enabling the detection of Earth-mass planets around Sun-like stars. New calibration techniques such as laser frequency combs and stabilized etalons ensure that the instrumental stability is well characterized. However, additional sources of error include stellar noise, undetected short-period planets, and telluric contamination. To understand and ultimately mitigate error sources, the contributing terms in the error budget must be isolated to the greatest extent possible. Here, we introduce a new high-cadence RV program, the Extreme Precision Spectrograph (EXPRES) 100 Earths Survey, which aims to identify rocky planets around bright, nearby G and K dwarfs. We also present a benchmark case: the 62 day orbit of a Saturn-mass planet orbiting the chromospherically quiet star, HD 3651. The combination of high eccentricity (0.6) and a moderately long orbital period ensures significant dynamical clearing of any inner planets. Our Keplerian model for this planetary orbit has a residual rms of 58 cm s−1 over a ∼6 month time baseline. By eliminating significant contributors to the RV error budget, HD 3651 serves as a standard for evaluating the long-term precision of extreme precision RV programs.