发表机构
Saint Petersburg State University; Special Astrophysical Observatory, Russian Academy of Sciences（圣彼得堡国立大学; 俄罗斯科学院特别天文台）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究对TOI-1408系外行星系统进行自洽分析，确认轨道构型但发现似然函数多峰，导致行星b半径约束不佳，并强调天体物理先验对模型结果的关键影响。
AI 中文摘要
我们对TOI-1408的多普勒和测光TESS及地面凌星观测进行了自洽分析。已知该恒星系统拥有两颗行星，其轨道接近2:1平均运动共振，并存在一个遥远的伴星。总体上，我们确认了先前研究得出的轨道构型，但发现似然函数包含多个局部极大值，散布在更广泛的参数域上，这使得部分模型不确定性显著大于之前的估计。特别是，由于近切向凌星几何，行星b的半径仍然约束不佳（从约1.2倍木星半径到约3.5倍木星半径）。我们还表明，所得到的模型对天体物理（基于光谱的）恒星质量M*和半径R*约束的先验非常敏感。虽然这些估计可能为拟合提供重要信息，但必须先验分布被精确指定才能发挥作用。目前，文献中尚无如此精确的表征（例如M*与R*之间的相关性）。
英文摘要
We perform a self-consistent analysis of Doppler and photometric TESS and ground-based transit observations available for TOI-1408, known to host a system with two planets orbiting near 2:1 mean-motion commensurability and a distant companion. In general we confirm its orbital configuration derived in previous studies, however we found that the likelihood function contains multiple local maxima spread over a wider parametric domain, thus making some model uncertainties significantly larger than deemed before. In particular, the planet b radius still appears poorly constrained (from $\sim 1.2$~$R_{\rm Jup}$ to $\sim 3.5$~$R_{\rm Jup}$) because of the near-tangential transit geometry. We also show that the derived model is very prior-dependent regarding the astrophysical (spectrum-derived) constraints on the stellar mass $M_\star$ and radius $R_\star$. While such estimations may potentially contribute a significant information to the fit, their prior distribution must be accurately specified to be useful. Presently so accurate characterization (e.g. the correlation between $M_\star$ and $R_\star$) is not available in the literature.
Comments23 pages, 11 figures, 2 tables; accepted by Research in Astronomy & Astrophysics
