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Related papers: Measuring Polarization in microlensing events

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Gravitational microlensing, when finite size source effects are relevant, provides an unique tool for the study of source star stellar atmospheres through an enhancement of a characteristic polarization signal. This is due to the…

Astrophysics of Galaxies · Physics 2015-06-11 G. Ingrosso , S. Calchi Novati , F. De Paolis , Ph. Jetzer , A. A. Nucita , F. Strafella , A. F. Zakharov

We present an analysis of the potential follow-up polarimetry microlensing observation to study the stellar atmospheres of the distant stars. First, we produce synthetic microlensing events using the Galactic model, stellar population, and…

Solar and Stellar Astrophysics · Physics 2021-01-20 Elahe Khalouei , Sedighe Sajadian , Sohrab Rahvar

The light received by source stars in microlensing events may be significantly polarized if both an efficient photon scattering mechanism is active in the source stellar atmosphere and a differential magnification is therein induced by the…

Solar and Stellar Astrophysics · Physics 2015-06-17 G. Ingrosso , F. De Paolis , A. A. Nucita , F. Strafella , S. Calchi Novati , Ph. Jetzer , G. Liuzzi , A. Zakharov

Gravitational microlensing, in case of relevant finite source size effects, provides an unique tool for the study of stellar atmospheres through the enhancement of a characteristic polarization signal. Here, we consider a set of highly…

Astrophysics of Galaxies · Physics 2013-04-23 A. A. Nucita , G. Ingrosso , F. De Paolis , F. Strafella , S. Calchi-Novati , Ph. Jetzer , A. F. Zakharov

The gravitational microlensing as a unique astrophysical tool can be used for studying the atmosphere of stars thousands of parsec far from us. This capability results from the bending of light rays in the gravitational field of a lens…

Solar and Stellar Astrophysics · Physics 2015-08-06 Sedighe Sajadian , Sohrab Rahvar

Much interest has been generated recently by the ongoing MACHO, EROS and OGLE projects to identify gravitationally lensed stars from the Large Magellanic Cloud and Galactic bulge, and the positive identification of several events (Alcock et…

Astrophysics · Physics 2007-05-23 J. F. L. Simmons , J. P. Willis , A. Newsam

We develop a new method to measure source proper motions in microlensing events, which can partially overcome problems due to blending. It takes advantage of the fact that the source position is known precisely from the microlensing event…

It is well known that the polarization signal in microlensing events of hot stars is larger than that of main-sequence stars. Most hot stars rapidly rotate around their stellar axes. The stellar rotation makes ellipticity and…

Solar and Stellar Astrophysics · Physics 2016-07-20 Sedighe Sajadian

We search OGLE-I photometric database for stars, which, as defined by formal criteria adopted by OGLE-I microlensing search, showed variability during only one out of 3 or 4 observing seasons. The results include 17 previously reported…

Astrophysics · Physics 2007-05-23 Przemyslaw Wozniak , Michal Szymanski

We study the benefits of polarimetry observations of microlensing events to detect and characterize circumstellar disks around the microlensed stars located at the Galactic bulge. These disks which are unresolvable from their host stars…

Solar and Stellar Astrophysics · Physics 2016-05-11 Sedighe Sajadian , Sohrab Rahvar

Microlensing events are usually selected among single-peaked non-repeating light curves in order to avoid confusion with variable stars. However, a microlensing event may exhibit a second microlensing brightening episode when the source…

Astrophysics · Physics 2009-11-13 J. Skowron , L. Wyrzykowski , S. Mao , M. Jaroszynski

A close-in giant planetary (CGP) system has a net polarization signal whose value varies depending on the orbital phase of the planet. This polarization signal is either caused by the stellar occultation or by reflected starlight from the…

Earth and Planetary Astrophysics · Physics 2017-04-07 Sedighe Sajadian , Markus Hundertmark

Optical starlight can be partially polarized while propagating through the dusty, magnetized interstellar medium. The polarization efficiency describes the polarization intensity fraction per reddening unit, P$_V$/E($B-V$), related to the…

The high gradient of magnification across the source during both small impact parameter events and caustic crossings offers a unique opportunity for determining the surface brightness profile of the source. Furthermore, models indicate that…

Astrophysics · Physics 2010-04-08 R. Ignace , J. E. Bjorkman , H. M. Bryce

The number and properties of observed gravitational microlensing events depend on the distribution and kinematics of stars and other compact objects along the line of sight. In particular, precise measurements of the microlensing optical…

We develop a new method of modeling microlensing events based on a Monte Carlo simulation that incorporates both a Galactic model and the constraints imposed by the observed characteristics of the event. The method provides an unbiased way…

In this work, we investigate if gravitational microlensing can magnify the polarization signal of a stellar spot and make it be observable. A stellar spot on a source star of microlensing makes polarization signal through two channels of…

Solar and Stellar Astrophysics · Physics 2015-08-06 Sedighe Sajadian

The probability of detecting a planetary companion of a lensing star during a microlensing event toward the Galactic center, averaged over all relevant event and galactic parameters, when the planet-star mass ratio $q=0.001$ has a maximum…

Astrophysics · Physics 2009-11-06 S. J. Peale

If a microlensing event is caused by a star, the event can exhibit change in color due to the light from the lens. In the previous and current lensing surveys, the color shift could not be used to constrain the lens population because the…

Astrophysics · Physics 2009-11-13 Byeong-Gon Park , Cheongho Han
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