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Related papers: Detecting stellar spots through polarimetry observ…

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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

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

Here, we revisit the polarization signal in caustic-crossing binary microlensing and introduce the maps of the polarization signals of the source star as a function of its position projected on the lens plane. The behavior of these maps…

Instrumentation and Methods for Astrophysics · Physics 2019-06-05 Sedighe Sajadian

Recently, Heyrovsk\'y & Sasselov (1999) investigated the sensitivity of {\it single-lens} gravitational microlensing event light curves to small spots and found that during source transit events spots can cause deviations in amplification…

Astrophysics · Physics 2009-10-31 Cheongho Han , Ho-Il Kim , Kyungae Chang , Seong-Hong Park

In a microlensing event, a large magnification occurs at caustic crossing and provides an opportunity to obtain a stronger signal associated with the object. In this paper we study the possibility of magnetic field detection in a…

Solar and Stellar Astrophysics · Physics 2015-08-04 Ahmad Mehrabi , Habib khosroshahi , Hadi Rahmani

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

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

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

During microlensing events with a small impact parameter, the amplification of the source flux is sensitive to the surface brightness distribution of the source star. Such events provide a means for studying the surface structure of target…

Astrophysics · Physics 2009-10-31 David Heyrovsky , Dimitar Sasselov

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

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

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

In gravitational microlensing, binary systems may act as lenses or sources. Identifying lens binarity is generally easy especially in events characterized by caustic crossing since the resulting light curve exhibits strong deviations from…

Solar and Stellar Astrophysics · Physics 2016-06-08 A. A. Nucita , F. De Paolis , G. Ingrosso , M. Giordano , L. Manni

One of the important microlensing applications to stellar atmospheres is the study of spots on stellar surface provided by the high resolution of caustic-crossing binary-lens events. In this paper, we investigate the characteristics of…

Solar and Stellar Astrophysics · Physics 2014-11-20 Kyu-Ha Hwang , Cheongho Han

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

We investigate the pattern of anomalies in the light curves of caustic-crossing binary microlensing events induced by spot(s) on the lensed source star. For this purpose, we perform simulations of events with various models of spots. From…

Astrophysics · Physics 2009-11-07 Heon-Young Chang , Cheongho Han

An extra-solar planet can be detected by microlensing because the planet can perturb the smooth lensing light curve created by the primary lens. However, it was shown by Gaudi that a subset of binary-source events can produce light curves…

Astrophysics · Physics 2009-11-06 Cheongho Han

With several detections, the technique of gravitational microlensing has proven useful for studying planets that orbit stars at Galactic distances, and it can even be applied to detect planets in neighbouring galaxies. So far, planet…

Astrophysics · Physics 2010-11-02 S. Rahvar , M. Dominik

We study the wave optics features of gravitational microlensing by a binary lens composed of a planet and a parent star. In this system, the source star near the caustic line produces a pair of images in which they can play the role of…

Earth and Planetary Astrophysics · Physics 2015-06-05 Ahmad Mehrabi , Sohrab Rahvar

We investigate the effect of a finite source on the planetary-lensing signals of high-magnification events. From this, we find that the dependency of the finite-source effect on the caustic shape is weak and perturbations survive even when…

Astrophysics · Physics 2011-02-11 Cheongho Han , Doeon Kim
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