Masses for free-floating planets and dwarf planets

作     者：Andrew Gould Wei-Cheng Zang Shude Mao Su-Bo Dong Andrew Gould;臧伟呈;毛淑德;东苏勃

作者机构：Max-Planck-Institute for AstronomyKonigstuhl 17D-69117 HeidelbergGermany Department of AstronomyOhio State University140 W.18th Ave.ColumbusOH 43210USA Department of AstronomyTsinghua UniversityBeijing 100084China National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China Kavli Institute for Astronomy and AstrophysicsPeking UniversityBeijing 100871China 

出 版 物：《Research in Astronomy and Astrophysics》 (天文和天体物理学研究（英文版）)

年 卷 期：2021年第21卷第6期

页      面：207-221页

核心收录：

学科分类：07[理学] 070401[理学-天体物理] 0704[理学-天文学] 

基　　金：support by the National Science Foundation of China (Grant Nos. 11821303 and 11761131004) supported by National Key R&D Program of China No.2019YFA0405100 

主　　题：gravitational lensing:micro 

摘      要：The mass and distance functions of free-floating planets(FFPs) would give major insights into the formation and evolution of planetary systems, including any systematic differences between those in the disk and bulge. We show that the only way to measure the mass and distance of individual FFPs over a broad range of distances is to observe them simultaneously from two observatories separated by D ~ O(0.01 au)(to measure their microlens parallax πE) and to focus on the finite-source point-lens(FSPL) events(which yield the Einstein radius θE). By combining the existing KMTNet 3-telescope observatory with a 0.3 m 4 deg2 telescope at L2, of order 130 such measurements could be made over four years, down to about M ~ 6 M⊕for bulge FFPs and M ~ 0.7 M⊕for disk FFPs. The same experiment would return masses and distances for many bound planetary systems. A more ambitious experiment, with two 0.5 m satellites(one at L2 and the other nearer Earth) and similar camera layout but in the infrared, could measure masses and distances of sub-Moon mass objects, and thereby probe(and distinguish between) genuine sub-Moon FFPs and sub-Moon dwarf planets in exo-Kuiper Belts and exo-Oort Clouds.