发表机构
European Space Agency; Main Astronomical Observatory, National Academy of Sciences of the Ukraine; Instituto de Astrofísica de Canarias; Université de Genève（欧洲空间局; 乌克兰国家科学院主天文台; 加那利群岛天体物理研究所; 日内瓦大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
通过甚大望远镜FORS2对附近L矮星DE1253-57进行八年天体测量监测，发现亚木星质量系外行星候选体PALTA-1 b，质量约0.54-0.77木星质量，若确认将成为罕见的围绕超冷矮星的巨行星。
AI 中文摘要
我们报告发现了PALTA-1 b，这是一颗亚木星质量的系外行星候选体，围绕附近的早L型矮星DENIS-P J1253108-570924（DE1253-57）运行，该矮星距离约17秒差距。该系外行星是通过使用甚大望远镜上的FORS2仪器对这颗L矮星的天体测量运动进行超过八年的监测，并表征其与预期单源运动的偏差而发现的。根据超冷矮星宿主不确定的质量，估计行星质量介于0.54倍木星质量和0.77倍木星质量之间。该系统的质量比约为0.010，相对分离距离估计为1.6-3.4天文单位。如果得到确认，PALTA-1 b将成为已知的极少数围绕附近超冷矮星运行的巨行星之一。这一发现完成了一项更大的天体测量行星搜索巡天，该巡天以20颗附近的超冷矮星为目标，此前已发现了三个新的超冷双星系统。
英文摘要
We report the discovery of PALTA-1 b, a sub-Jupiter mass exoplanet candidate orbiting the nearby early-L dwarf DENIS-P J1253108-570924 (DE1253-57) located at a distance of ~17 pc. The exoplanet was discovered by monitoring the L dwarf's astrometric motion with FORS2 at the Very Large Telescope over more than eight years and characterising the deviations from the expected single-source motion. The estimated planet mass is between 0.54 MJup and 0.77 MJup, depending on the uncertain mass of the ultracool dwarf host. The system's mass ratio is about 0.010, and the relative separation is estimated at 1.6-3.4 au. If confirmed, PALTA-1 b would be one of the very few known examples of a giant planet orbiting a nearby ultracool dwarf. This discovery finalises a larger astrometric planet search survey that targeted 20 nearby ultracool dwarfs and previously discovered three new ultracool binary systems.
Comments12 pages, 10 figures. Accepted for publication in A&A
