[论文解读] The Occurrence Rate of Nearby Planetary Companions to Hot Jupiters

Lizhou Sha, Andrew M. Vanderburg+25 more|arXiv (Cornell University)|Jan 19, 2026

Stellar, planetary, and galactic studies被引用 0

一句话总结

作者对热木星在前五年 TESS 数据中进行统一盒形最小二乘法搜索，以寻找附近的过境伴星，获得 7.6% 的发生率及不确定性，并讨论对热木星形成的含义。

ABSTRACT

Of the > 500 confirmed transiting hot jupiters and approximately 2000 additional candidates today, only ten are known to have nearby companion planets. The survival of nearby companions means that these hot jupiters cannot have migrated to their present location via dynamically disruptive high-eccentricity migration but instead have undergone disk migration or formed in situ. The occurrence rate for these nearby companions, therefore, constrains the relative efficiency of different hot jupiter formation pathways. Here, we perform a uniform box least-squares search for nearby transiting companions to hot jupiters in the first five years of TESS data. Accounting for observational completeness and detection efficiency, we arrive at an occurrence rate of $(7.6^{+5.5}_{-3.8})\%$, which is a lower limit on the fraction of hot jupiters that underwent disk migration or in situ formation. Comparing this rate with that derived from transit-timing variation searches suggests that hot jupiters are likely mostly aligned with their nearby companions, but their apparently higher incidence of grazing transits may point to a slight preferential misalignment. We also synthesize evidence that hot jupiters with nearby companions may have cold companions at a rate similar to that of other hot jupiters. Comprehensive transit, radial velocity, and stellar obliquity measurements in hot jupiter systems with nearby companions will be necessary to fully account for the relative prevalence of proposed hot jupiter formation pathways.

研究动机与目标

• 通过测量内伴星来约束通过盘迁移或就地形成形成的热木星分数。
• 对前五年的 TESS 数据应用统一管线，搜索热木星附近的过境伴星。
• 考虑观测完整性和假阳性，推导发生率（eta）。
• 将结果与过境时变（TTV）研究进行比较，评估轨道对准性与掠入过境的含义。
• 讨论后续观测的要求，以全面理解热木星形成路径。

提出的方法

• 从 TOI 目录中组装 P<10 d 的热木星样本，并结合 TFOPWG 安排和 Gaia RV 检查对假阳性进行筛选。
• 应用统一的光变曲线分析管线（QLP 数据）、盒形最小二乘法搜索、通过 Keplerspline 的去趋势和迭代信号去除来识别额外的短周期行星。
• 人工和自动对过境样本信号进行筛选，包括质心分析和历元匹配，以排除假阳性和次级蚀变。
• 进行注入-检回模拟，以绘制传输信噪比（S/N）与探测效率的关系，并拟合 gamma CDF 将 S/N 转换为探测概率。
• 利用观测到的探测（六个内伴星）以及以完整性校正后的有效样本量，通过贝叶斯 Beta 后验分布计算伴星发生率。
• 估算假阳性率并将其并入发生率计算的有效样本量。

Figure 1: The distribution of the host stars of the selected hot jupiters. Left: The histogram of stellar mass. Right: The color–magnitude diagram.

实验结果

研究问题

• RQ1 前五年 TESS 数据中热木星附近过境伴星的发生率是多少？
• RQ2 所测得的发生率如何约束热木星形成路径（盘迁移、高偏心迁移 vs 就地形成）？
• RQ3 带有附近伴星的热木星是否通常与这些伴星对准，掠入过境在其中起何作用？
• RQ4 与其他热木星相比，是否存在内伴星的热木星也同样多地拥有冷伴星？

主要发现

• 在样本中检测到六个热木星内伴星。
• 导出发生率 eta = 7.6%，不确定性为 +5.5% / -3.8%。
• 该比率是热木星通过盘迁移或就地形成形成比例的下限。
• 与 TTV 结果的比较表明热木星很可能在很大程度上与其附近伴星对准，掠入过境可能引起轻微的错位。
• 综合分析表明带有伴星的热木星可能在获得冷伴星方面的比例与其他热木星相似，强调需要进行全面的后续观测。

Figure 2: A scatter plot of $\sigma_{P}$ versus $\sigma_{T}$ for the detection of injected transit signals, similar to Figure 2 by J. L. Coughlin et al. ( 2014 ) . The thin blue lines denote the chosen significance levels for ephemeris matching in equation ( 4 ) and divides the plane into four quadr