AI 中文总结
研究宽轨道恒星伴星对 M 矮星周围热木星形成的影响，通过发现 TOI-5628Ab 系统，利用多种观测手段确定行星参数，基于盖亚 DR3 对特定 M 星进行搜索，发现短周期巨行星的 M 矮星恒星多重性更高，表明宽轨道伴星促进其形成，高偏心率迁移或起关键作用。
AI 中文摘要
双星普遍存在，但宽轨道恒星伴星如何影响热木星的形成仍不清楚，尤其是在 M 矮星周围。本文首次报告发现 TOI-5628Ab，这颗巨行星每 4.34 天凌日一颗中等质量 M 矮星（$M_\ast=0.36\pm0.02\ M_\odot$），并伴有一颗白矮星 TOI-5628B（$M_{\rm WD}=0.59\pm0.16\ M_\odot$），投影距离约 2500 天文单位。利用 TESS、地基测光和 SPIRou RVs 等手段，确定了行星半径为$0.74\pm0.04\ R_J$，质量为$0.09\pm0.04\ M_J$，$3\sigma$上限为$0.22\ M_J$。在此基础上，基于盖亚 DR3 的恒星运动学，对所有周期小于 10 天、半径大于 0.7 $R_J$的已确认有巨行星的 M 矮星以及一组与行星样本恒星性质相似的野外观测 M 星，进行了均匀系统搜索，寻找投影半长轴在 100 至 10000 天文单位之间的共动恒星伴星。结果显示，拥有短周期巨行星的 M 矮星的恒星多重性为$34.2\pm9.5\%$，远高于野外观测 M 星的$5.3\pm3.7\%$，约为其 6 倍。研究表明宽轨道恒星伴星倾向于促进质量在$0.21 \leq M_\ast\leq 0.64\ M_\odot$的 M 星周围短周期巨行星形成，高偏心率迁移可能起重要作用。
英文摘要
Binary stars are ubiquitous, yet it remains unclear how wide-orbit stellar companions influence the formation of hot Jupiters, particularly around M dwarfs. Here, we first report the discovery of TOI-5628Ab, a giant planet transiting a mid-type M dwarf ($M_\ast=0.36\pm0.02\ M_\odot$) every 4.34 days, accompanied by an associated white dwarf TOI-5628B ($M_{\rm WD}=0.59\pm0.16\ M_\odot$) at a projected distance of about 2,500 AU. Using TESS, ground-based photometry and SPIRou RVs, we constrain the planet radius to $0.74\pm0.04\ R_J$ and mass to $0.09\pm0.04\ M_J$, with a $3σ$ upper limit of $0.22\ M_J$. Building on this system, we further conduct a homogeneous systematic search for co-moving stellar companions with projected semi-major axis between 100 and 10,000 AU around all M dwarfs with confirmed giant planets with periods smaller than 10 days and radii larger than 0.7 $R_J$, as well as a group of field M stars with stellar properties similar to the planet sample, based on the stellar kinematics from Gaia DR3. We measure a stellar multiplicity of $34.2\pm9.5\%$ for M dwarfs hosting short-period giant planets, which is substantially higher than the fraction of $5.3\pm3.7\%$ for the field M stars by approximately a factor of 6. Our results suggest that wide-orbit stellar companions tend to promote the formation of short-period giant planets around M stars with masses $0.21 \leq M_\ast\leq 0.64\ M_\odot$, and high-eccentricity migration may play an important role in producing such systems.
Comments20 pages, 7 figures, 3 tables, accepted for publication in ApJL
