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Related papers: Short-duration lensing events: II. Expectations an…

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Short duration lensing events tend to be generated by low-mass lenses or by lenses with high transverse velocities. Furthermore, for any given lens mass and speed, events of short duration are preferentially caused by nearby lenses…

Earth and Planetary Astrophysics · Physics 2015-05-14 Rosanne Di Stefano

We analyze three years (1998-2000) of OGLE observations of microlensing events to place limits on the abundance of planets with a planet-to-star mass ratio $q=10^{-3}$ at distances $\sim 1-4$AU from their host stars, i.e. `cool Jupiters'.…

Astrophysics · Physics 2009-11-07 Yiannis Tsapras , Keith Horne , Stephen Kane , Richard Carson

Some low-mass planets are expected to be ejected from their parent planetary systems during early stages of planetary system formation. According to planet-formation theories, such as the core accretion theory, typical masses of ejected…

Planet formation theories predict the existence of free-floating planets that have been ejected from their parent systems. Although they emit little or no light, they can be detected during gravitational microlensing events. Microlensing…

We compute the predicted optical depth and duration distribution of microlensing events towards Baade's window in a model composed of a Galactic disk and a bar. The bar model is a self-consistent dynamical model built out of individual…

Astrophysics · Physics 2009-10-22 HongSheng Zhao , David N. Spergel , R. Michael Rich

We present measurements of the microlensing optical depth and event rate toward the Galactic bulge using the dataset from the 2006--2014 MOA-II survey, which covers 22 bulge fields spanning ~42 deg^2 between -5 deg < l < 10 deg and -7 deg <…

We analyze the data of the gravitational microlensing survey carried out by by the MOA group during 2000 towards the Galactic Bulge (GB). Our observations are designed to detect efficiently high magnification events with faint source stars…

We describe the discovery of the longest microlensing event ever observed, OGLE-1999-BUL-32, also independently identified by the MACHO collaboration as MACHO-99-BLG-22. This unique event has an Einstein radius crossing time of 641 days.…

The MACHO and OGLE collaborations have argued that the three longest duration bulge microlensing events are likely caused by nearby black holes, given the small velocities measured with microlensing parallax and nondetection of the lenses.…

Astrophysics · Physics 2009-11-07 Eric Agol , Marc Kamionkowski , Leon Koopmans , Roger Blandford

We present measurements of the microlensing optical depth and event rate toward the Galactic Bulge based on two years of the MOA-II survey. This sample contains ~1000 microlensing events, with an Einstein Radius crossing time of t_E < 200…

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…

With their excellent photometric precision and dramatic increase in monitoring frequency, future microlensing survey experiments are expected to be sensitive to very short time-scale, isolated events caused by free-floating and…

Astrophysics · Physics 2009-11-10 Cheongho Han , B. Scott Gaudi , Jin H. An , Andrew Gould

The analysis of the first three years of the OGLE data revealed 12 microlensing events of the Galactic bulge stars, with the characteristic time scales in the range $ 8.6 < t_0 < 80 $ days, where $ t_0 = R_E / V $. A complete sample of nine…

In the companion paper we began the task of systematically studying the detection of planets in wide orbits ($a > 1.5 R_E$) via microlensing surveys. In this paper we continue, focusing on repeating events. We find that, if all planetary…

Astrophysics · Physics 2009-10-31 Rosanne Di Stefano , Richard A. Scalzo

We study the statistics and properties of microlensing events that can be detected by the Transiting Exoplanet Survey Satellite(TESS) based on Monte Carlo simulations. We simulate potential microlensing events from a sample of the TESS…

Earth and Planetary Astrophysics · Physics 2024-08-27 Sedighe Sajadian , Atousa Kalantari , Hossein Fatheddin , Somayeh Khakpash

Perhaps as many as 30 parallax microlensing events are known, thanks to the efforts of the MACHO, OGLE, EROS and MOA experiments monitoring the bulge. Using Galactic models, we construct mock catalogues of microlensing light curves towards…

Astrophysics · Physics 2009-11-11 M. C. Smith , V. Belokurov , N. W. Evans , S. Mao , J. H. An

Modern surveys of gravitational microlensing events have progressed to detecting thousands per year. Surveys are capable of probing Galactic structure, stellar evolution, lens populations, black hole physics, and the nature of dark matter.…

We present the details of the Bayesian analysis on the planetary microlensing event MOA-2016-BLG-227, whose excess flux is likely due to a source/lens companion or an unrelated ambient star, as well as of the assumed prior distributions.…

Earth and Planetary Astrophysics · Physics 2020-05-27 Naoki Koshimoto , David P. Bennett , Daisuke Suzuki
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