论文标题
在微透镜事件中，自由浮动或宽轨道行星Ogle-2019-Blg-0551
A free-floating or wide-orbit planet in the microlensing event OGLE-2019-BLG-0551
论文作者
论文摘要
通过微透镜调查对银河系凸起的高度观察导致发现了一些极短的短次微透明事件，这些事件可归因于自由浮动或宽大的行星。在这里，我们报告了另一个强烈的自由浮动行星候选者的发现，这是从重力微透镜事件OGLE-2019-BLG-0551的分析中发现的。事件的光曲线的特征是持续时间很短（<3 d）和很小的振幅（<0.1 mag）。 From modeling of the light curve, we find that the Einstein timescale, tE = 0.381 +/- 0.017 d, is much shorter, and the angular Einstein radius, thetaE = 4.35 +/- 0.34 uas, is much smaller than those of typical lensing events produced by stellar-mass lenses (tE ~ 20 d, thetaE ~ 0.3 mas), indicating that the lens is very likely to be a行星质量对象。我们对活动的光曲线中的同伴恒星进行了广泛的搜索，并没有为假定的宿主星找到明显的证据。我们还第一次证明了镜头的角度爱因斯坦半径并不取决于在具有强有限源效应的低磁化事件中混合。
High-cadence observations of the Galactic bulge by the microlensing surveys led to the discovery of a handful of extremely short-timescale microlensing events that can be attributed to free-floating or wide-orbit planets. Here, we report the discovery of another strong free-floating planet candidate, which was found from the analysis of the gravitational microlensing event OGLE-2019-BLG-0551. The light curve of the event is characterized by a very short duration (<3 d) and a very small amplitude (< 0.1 mag). From modeling of the light curve, we find that the Einstein timescale, tE = 0.381 +/- 0.017 d, is much shorter, and the angular Einstein radius, thetaE = 4.35 +/- 0.34 uas, is much smaller than those of typical lensing events produced by stellar-mass lenses (tE ~ 20 d, thetaE ~ 0.3 mas), indicating that the lens is very likely to be a planetary-mass object. We conduct an extensive search for possible signatures of a companion star in the light curve of the event, finding no significant evidence for the putative host star. For the first time, we also demonstrate that the angular Einstein radius of the lens does not depend on blending in the low-magnification events with strong finite source effects.
