$Spitzer$ 微引力透镜视差揭示一颗逆向自转的低质量棕矮星 OGLE-2017-BLG-0896
太阳与恒星天体物理
2019-02-20 v2
摘要
银河系中超出太阳邻域的孤立棕矮星的运动学实际上未知。微引力透镜有潜力探测这一隐藏种群，因为它甚至可以测量暗孤立透镜的质量和六维相空间坐标中的五个（除径向速度外）。然而，为了恢复完整信息，需要同时测量微引力透镜视差和有限源效应。在此，我们将 卫星视差测量与表现出强有限源效应的地面光变曲线（事件 OGLE-2017-BLG-0896）相结合。我们找到了透镜的两个简并解（由于已知的卫星视差简并性），除自行外彼此一致。该透镜是一颗孤立棕矮星，质量为 或 。这是迄今为止测得的最低孤立天体质量，仅比太阳金属度下理论氘融合边界（即自由漂浮行星的常规定义）重约 45%。该棕矮星位于朝向银河系核球方向 kpc 或 kpc 处，但其自行方向与盘星相反，其中一个解表明它正在银道面内运动。虽然它可能是晕族棕矮星，但也可能代表一个不同的未知种群。
引用
@article{arxiv.1805.08778,
title = {$Spitzer$ Microlensing Parallax for OGLE-2017-BLG-0896 Reveals a Counter-Rotating Low-Mass Brown Dwarf},
author = {Yossi Shvartzvald and Jennifer C. Yee and Jan Skowron and Chung-Uk Lee and Andrzej Udalski and Sebastiano Calchi Novati and Valerio Bozza and Charles A. Beichman and Geoffery Bryden and Sean Carey and B. Scott Gaudi and Calen B. Henderson and Wei Zhu and Etienne Bachelet and Greg Bolt and Grant Christie and Dan Maoz and Tim Natusch and Richard W. Pogge and Rachel A. Street and Thiam-Guan Tan and Yiannis Tsapras and Paweł Pietrukowicz and Igor Soszyński and Michał K. Szymański and Przemek Mróz and Radoslaw Poleski and Szymon Kozłowski and Krzysztof Ulaczyk and Michał Pawlak and Krzysztof A. Rybicki and Patryk Iwanek and Michael D. Albrow and Sang-Mok Cha and Sun-Ju Chung and Andrew Gould and Cheongho Han and Kyu-Ha Hwang and Youn Kil Jung and Dong-Jin Kim and Hyoun-Woo Kim and Seung-Lee Kim and Dong-Joo Lee and Yongseok Lee and Byeong-Gon Park and Yoon-Hyun Ryu and In-Gu Shin and Weicheng Zang and Martin Dominik and Christiane Helling and Markus Hundertmark and Uffe G. Jørgensen and Penelope Longa-Peña and Stephen Lowry and Sedighe Sajadian and Martin J. Burgdorf and Justyn Campbell-White and Simona Ciceri and Daniel F. Evans and Yuri I. Fujii and Tobias C. Hinse and Sohrab Rahvar and Markus Rabus and Jesper Skottfelt and Colin Snodgrass and John Southworth},
journal= {arXiv preprint arXiv:1805.08778},
year = {2019}
}
备注
17 pages, 3 figures, 2 tables. Accepted for publication in The Astronomical Journal