Improving circumbinary planet detections by fitting their binary's apsidal precession
Improving circumbinary planet detections by fitting their binary's apsidal precession
复制标题
通过拟合双星的近轴进动来改善绕双星行星的探测
DOI：
10.1093/mnras/stad607
复制
发表时间：
2023
影响因子：
4.8
通讯作者：
Baycroft T
中科院分区：
文献类型：
--
作者：
Baycroft T
近点进动是影响星星系统径向速度的主要非开普勒动力学效应。它的存在可以明显地隐藏环绕双星行星的存在，因为许多拟合算法假设完美的开普勒运动。对于一阶，拱点进动（）可以通过在通常的开普勒模型中添加线性项来解释。我们在thekimapackage中包括拱点进动，这是一个轨道拟合器，旨在从径向速度数据中检测和表征行星。在本文中，我们详细介绍了这一点和其他补充tokima，提高拟合恒星双星和circumbinary行星，包括广义相对论的修正。然后，我们证明，拟合forcan提高检测灵敏度到环双星系外行星的数量级在某些情况下，特别是在多行星系统的情况下。此外，我们将该算法应用于几个真实的系统，在KOI-126（一个紧三元系）中产生了一个新的aspidal岁差测量，并在Kepler-16环双星系统中检测到。尽管Kepler-16检测到了拱点岁差，但它对检测极限或行星参数没有太大影响。我们还推导出一个表达式的进动外行星将导致内部的二元和比较的值，这预测与我们检测到的。
Apsidal precession in stellar binaries is the main non-Keplerian dynamical effect impacting the radial-velocities of a binary star system. Its presence can notably hide the presence of orbiting circumbinary planets because many fitting algorithms assume perfectly Keplerian motion. To first order, apsidal precession () can be accounted for by adding a linear term to the usual Keplerian model. We include apsidal precession in thekimapackage, an orbital fitter designed to detect and characterize planets from radial velocity data. In this paper, we detail this and other additions tokimathat improve fitting for stellar binaries and circumbinary planets including corrections from general relativity. We then demonstrate that fitting forcan improve the detection sensitivity to circumbinary exoplanets by up to an order of magnitude in some circumstances, particularly in the case of multiplanetary systems. In addition, we apply the algorithm to several real systems, producing a new measurement of aspidal precession in KOI-126 (a tight triple system), and a detection ofin the Kepler-16 circumbinary system. Although apsidal precession is detected for Kepler-16, it does not have a large effect on the detection limit or the planetary parameters. We also derive an expression for the precession an outer planet would induce on the inner binary and compare the value this predicts with the one we detect.