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Related papers: Towards Locating the Brightest Microlensing Events…

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Microlensing has established itself as a powerful new method for the detection of baryonic dark matter in the Galaxy. The theory of microlensing is sketched and its similarity with the optical effect of twinkling is explained. The bulk of…

Astrophysics · Physics 2007-05-23 Wyn Evans

Microlensing searches aim to detect compact halo dark matter via its gravitational lensing effect on stars within the Large Magellanic Cloud. The most recent results have led to the claim that roughly one fifth of the galactic halo dark…

Astrophysics · Physics 2009-11-07 Anne M Green , Karsten Jedamzik

We report the observation of the first gravitational microlensing event in a sparse stellar field, involving the brightest (V=11.4 mag) andclosest (~ 1 kpc) source star to date. This event was discovered by an amateurastronomer, A. Tago, on…

We report the detection of 45 candidate microlensing events in fields toward the Galactic bulge. These come from the analysis of 24 fields containing 12.6 million stars observed for 190 days in 1993. Many of these events are of extremely…

Here, we study the microlensing of radially pulsating stars. Discerning and characterizing the properties of distant, faint pulsating stars is achievable through high-cadence microlensing observations. Combining stellar variability period…

Solar and Stellar Astrophysics · Physics 2020-04-22 Sedighe Sajadian , Richard Ignace

Gravitational lensing describes the bending of the trajectories of light and gravitational waves due to the gravitational potential of a massive object. Strong lensing by galaxies can create multiple images with different overall…

General Relativity and Quantum Cosmology · Physics 2024-02-26 Simon M. C. Yeung , Mark H. Y. Cheung , Joseph A. J. Gais , Otto A. Hannuksela , Tjonnie G. F. Li

The relative transverse velocity of a lens with respect to the source star in gravitational lensing results in a frequency shift in the light rays passing by a lens. We propose using this relativistic effect for measuring the relative…

Astrophysics of Galaxies · Physics 2020-01-08 Sohrab Rahvar

Gravitational microlensing surveys target very dense stellar fields in the local group. As a consequence the microlensed source stars are often blended with nearby unresolved stars. The presence of `blending' is a cause of major uncertainty…

Astrophysics · Physics 2009-11-13 Martin C. Smith , Przemyslaw Wozniak , Shude Mao , Takahiro Sumi

We estimate the fraction of mass that is composed of compact objects in gravitational lens galaxies. This study is based on microlensing measurements (obtained from the literature) of a sample of 29 quasar image pairs seen through 20 lens…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 E. Mediavilla , J. A. Munoz , E. Falco , V. Motta , E. Guerras , H. Canovas , C. Jean , A. Oscoz , A. M. Mosquera

A complete manual search has been carried out of the list of 285423 objects, nearly all of them galaxies, identified in the COSMOS field that are brighter than I=25. Two certain and one highly probable new gravitational lenses are found, in…

Astrophysics · Physics 2009-11-13 Neal Jackson

Strongly lensed gravitational waves may pass through the stellar field of a lensing galaxy with additional modulations (on both phase and amplitude) due to gravitational microlensing effect of stars/remnants near the line of sight. These…

General Relativity and Quantum Cosmology · Physics 2025-10-21 Zhaoqi Su , Xikai Shan , Zhenwei Lyu , Junyao Zhang , Yebin Liu , Shude Mao , Huan Yang

Stellar microlensing is a powerful method to constrain compact dark matter models, uncover binary stars, and exoplanets during caustic crossing events. At cosmological distances, {\it James-Webb Space Telescope} ({\it JWST}) is routinely…

Astrophysics of Galaxies · Physics 2026-04-14 Sung Kei Li , Thomas Broadhurst , Jose M. Diego , Jeremy Lim , Jose M. Palencia , James Nianias

We present the analysis of the first two years of the OGLE search for gravitational lenses towards the Galactic bulge. We detected 9 microlensing events in an algorithmic search of $ \sim 10^8 $ measurements of $ \sim 10^6 $ stars. The…

When a source star is gravitationally microlensed by a dark lens, the centroid of the source star image is displaced relative to the position of the unlensed source star with an elliptical trajectory. Recently, routine astrometric follow-up…

Astrophysics · Physics 2009-10-31 Cheongho Han , Youngjin Jeong

We describe a new method to search for gravitational microlensing toward the Galactic bulge that employs a small camera rather than a conventional telescope and probes new regions of parameter space. The small aperture (~65 mm) permits…

Astrophysics · Physics 2009-10-30 Andrew Gould , D. L. DePoy

Stars in globular clusters can act either as sources for MACHOs (Massive Astrophysical Compact Halo Objects) located along the line of sight or as lenses for more distant background stars. Although the expected rate of microlensing events…

Astrophysics · Physics 2007-05-23 P. Jetzer , M. Strässle , U. Wandeler

Given the number of recently discovered galaxy-galaxy lens systems, we anticipate that a gravitationally lensed supernova will be observed within the next few years. We explore the possibility that stars in the lens galaxy will produce…

Astrophysics · Physics 2008-11-26 Gregory Dobler , Charles R. Keeton

We examine the possibility of observing gravitational lensing in the weak deflection regime by the supermassive black hole in the center of the galaxy M31. This black hole is significantly more massive than the black hole in the center of…

Astrophysics · Physics 2009-06-23 V. Bozza , S. Calchi Novati , L. Mancini

Due to dramatic improvements in the precision of astrometric measurements, the observation of light centroid shifts in observed stars due to intervening massive compact objects (`astrometric microlensing') will become possible in the near…

Astrophysics · Physics 2007-05-23 Martin Dominik , Kailash C. Sahu

Previous calculations of the rates and optical depths due to microlensing only considered resolved stars. However, if a faint unresolved star lens is close enough to a resolved star, the event will be seen by the microlensing experiments…

Astrophysics · Physics 2007-05-23 C. Alard