English
Related papers

Related papers: Interferometric observation of microlensing events

200 papers

We consider strong gravitational lensing by nearby stars. Using our wave-optical treatment of lensing phenomena, we study Einstein rings that may form around nearby stellar lenses. It is remarkable that these rings are bright and large…

Instrumentation and Methods for Astrophysics · Physics 2023-02-13 Slava G. Turyshev , Viktor T. Toth

Ongoing microlensing observations by OGLE and MOA regularly identify and conduct high-cadence sampling of lensing events with Einstein diameter crossing time, tau_E, of 16 or fewer days. Events with estimated values of tau_E of one to two…

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

The VISTA Variables in the Via Lactea (VVV) survey and its extension, have been monitoring about 560 square degrees of sky centred on the Galactic bulge and inner disc for nearly a decade. The photometric catalogue contains of order 10$^9$…

Astrophysics of Galaxies · Physics 2021-07-14 Andrea Husseiniova , Peter McGill , Leigh C. Smith , N. Wyn Evans

We show that one can measure the effects of microlens parallax for binary microlensing events with three well-measured peaks -- two caustic crossings plus a cusp approach, and hence derive the projected Einstein radius. Since the angular…

Astrophysics · Physics 2007-05-23 Jin H. An , Andrew Gould

Microlensing is able to reveal multiple body systems located several kilo-parsec away from the Earth. Since it does not require the measurement of light from the lens, microlensing is sensitive to a range of objects from free-floating…

Earth and Planetary Astrophysics · Physics 2018-10-17 E. Bachelet , J. -P. Beaulieu , I. Boisse , A. Santerne , R. A. Street

For microlensing case angular distances between images or typical astrometric shifts due to microlensing are about $10^{-5}-10^{-6} \mu as$. Such an angular resolution will be reached with the space space--ground interferometer Radioastron.…

Astrophysics · Physics 2007-05-23 Alexander F. Zakharov

Follow the big stars! I review the theory of detection and parameter measurement of planetary systems by follow-up observations of ongoing microlensing events. Two parameters can generically be measured from the event itself: the…

Astrophysics · Physics 2007-05-23 Andrew Gould

Gravitational microlensing has the potential to provide direct gravitational masses of single, free-floating brown dwarfs, independent of evolutionary and atmospheric models. The proper motions and parallaxes of nearby brown dwarfs can be…

Solar and Stellar Astrophysics · Physics 2022-11-30 Judah Luberto , Emily C. Martin , Peter McGill , Alexie Leauthaud , Andrew J. Skemer , Jessica R. Lu

A microlensing lensing zone refers to the range of planet-star separations where the probability of detecting a planetary signal is high. Its conventional definition as the range between $\sim 0.6$ and 1.6 Einstein radii of the primary lens…

Astrophysics · Physics 2011-02-11 Cheongho Han

The microlensing event OGLE-2011-BLG-0417 is an exceptionally bright lens binary that was predicted to present radial velocity variation at the level of several km/s. Pioneer radial velocity follow-up observations with the UVES spectrograph…

Microlensing is generally studied in the geometric optics limit. However, diffraction may be important when nearby substellar objects lens occult distant stars. In particular the effects of diffraction become more important as the…

Astrophysics of Galaxies · Physics 2010-10-05 Jeremy S. Heyl

We report the lens mass and distance measurements of the nearby microlensing event TCP J05074264+2447555. We measure the microlens parallax vector ${\pi}_{\rm E}$ using Spitzer and ground-based light curves with constraints on the direction…

The statistical distribution of the masses of planets about stars between the Sun and the center of the galaxy is constrained to within a factor of three by an intensive search for planets during microlensing events. Projected separations…

Astrophysics · Physics 2016-08-30 S. J. Peale

Microlensing searches toward the inner galaxy $(|l|,|b|\leq 22.\hskip-2pt'5)$ have several major advantages. First, the event rate is strongly dominated by bulge-bulge lensing events where both the source and lens lie in the bulge. Second,…

Astrophysics · Physics 2009-10-22 Andrew Gould

It has been shown that a flux--weighted full width at half maximum timescale of a microlensing event can be used in an unbiased estimator of the optical depth. For the first time, this allows a physical parameter to be easily estimated from…

Astrophysics · Physics 2009-10-31 Edward A. Baltz , Joseph Silk

We present an analysis of the longest timescale microlensing events discovered by the MACHO Collaboration during a 7 year survey of the Galactic bulge. We find 6 events that exhibit very strong microlensing parallax signals due, in part, to…

When there is more than one source of light along the line of sight to a gravitationally lensed object, the characteristics of the observed light curve are influenced by the presence of the light that is not lensed. In this paper we develop…

Astrophysics · Physics 2009-10-28 R. DiStefano , A. A. Esin

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

Microlensing can be used to discover exoplanets of a wide range of masses with orbits beyond ~ 1 AU, and even free-floating planets. The WFIRST mission will use microlensing to discover approximately 1600 planets by monitoring ~100 million…

Earth and Planetary Astrophysics · Physics 2021-01-12 Somayeh Khakpash , Matthew Penny , Joshua Pepper

We investigate the possibilities that pulsars act as the lens in gravitational microlensing events towards the galactic bulge or a spiral arm. Our estimation is based on expectant survey and observations of FAST (Five hundred meter Aperture…

High Energy Astrophysical Phenomena · Physics 2015-05-14 S. Dai , R. X. Xu , A. Esamdin