关于土星质量自由漂浮行星候选体KMT-2024-BLG-0792/OGLE-2024-BLG-0516宿主恒星的上限

中文摘要 AI 辅助

近期研究发现了许多短时标微引力透镜事件，这些事件被认为是由自由漂浮或宽轨道行星产生的。微引力透镜事件KMT-2024-BLG-0792/OGLE-2024-BLG-0516是目前唯一一个直接测量质量（$0.73^{+0.25}_{-0.15}$土星质量）的自由漂浮行星候选体，其质量来自地基和Gaia卫星联合观测。然而，目前尚不清楚透镜体是真正孤立存在，还是与一颗宽分离的宿主恒星束缚在一起。在此，我们报告了在峰值增亮两年后使用甚大望远镜干涉仪/GRAVITY仪器对该事件进行的高角分辨率干涉观测。在投影分离距离达90 au的范围内，我们未探测到任何发光的宿主恒星，这支持了透镜体确实是一颗自由漂浮行星的假说。我们推导出假定宿主恒星质量的5 sigma上限约为0.5-0.6 M_solar。这项工作表明，干涉测量法为在短时标和行星微引力透镜事件中直接搜索或约束宿主恒星提供了一种强有力的方法。

英文摘要

Recent studies found a number of short-timescale microlensing events that are thought to be produced by free-floating or wide-orbit planets. The microlensing event KMT-2024-BLG-0792/OGLE-2024-BLG-0516 is currently the only free-floating planet candidate with a directly measured mass ($0.73^{+0.25}_{-0.15}$ Saturn masses), derived from joint ground-based and Gaia satellite observations. However, it remains unclear whether the lens is truly isolated or bound to a widely separated host star. Here, we report high-angular-resolution interferometric observations of the event obtained with the Very Large Telescope Interferometer/GRAVITY instrument two years after peak magnification. We detect no luminous host star up to a projected separation of 90 au, supporting the hypothesis that the lens is indeed a free-floating planet. We derive a 5 sigma upper limit on the mass of a putative host star of approximately 0.5-0.6 M_solar. This work demonstrates that interferometry provides a powerful method for directly searching for or constraining host stars in short-duration and planetary microlensing events.

发表机构

• University of Warsaw（华沙大学）
• École Normale Supérieure, Paris（巴黎高等师范学院）
• European Southern Observatory（欧洲南方天文台）
• Peking University（北京大学）
• National Astronomical Observatories, Chinese Academy of Science（中国科学院国家天文台）

机构由 AI 辅助整理，请以论文原文为准。

补充信息

备注

Submitted to A&A