相关论文: Astrometric limits set by surface structure, binar…
Foundations of standard theory of microlensing are described, namely we consider microlensing stars in Galactic bulge, the Magellanic Clouds or other nearby galaxies. We suppose that gravitational microlenses lie between an Earth observer…
Gaia will observe more than one billion objects brighter than V=20, including stars, asteroids, galaxies and quasars. As Gaia performs real time detection (i.e. without an input catalogue) the intrinsic properties of most of these objects…
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…
Astrometry, the precise measurement of stellar positions and velocities, offers a promising approach to probing the low-frequency stochastic gravitational wave background (SGWB). Notably, astrometric vector sky maps are sensitive to…
We identify stars with large proper motions that are potential candidates for the astrometric microlensing effect during the Gaia mission i.e. between 2012 and 2019. The effect allows a precise measurement of the mass of a single star that…
This is a personal review of various issues related to massive photometric and astrometric searches. A complete inventory of variable stars down to almost any magnitude limit will improve our understanding of the stellar evolution and the…
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…
Precise measurement of the fundamental parameters of stellar systems, including mass and radius, depends critically on how well the stellar distances are known. Astrometry from space provides parallax measurements of unprecented accuracy,…
Extragalactic proper motions can reveal a variety of cosmological and local phenomena over a range of angular scales. These include observer-induced proper motions, such as the secular aberration drift caused by the solar acceleration about…
Observations of the clustering of galaxies can provide useful information about the distribution of dark matter in the Universe. In order to extract accurate cosmological parameters from galaxy surveys, it is important to understand how the…
The effect of gravitational microlensing on the intensity of gravitational radiation as it propagates through an inhomogeneous medium containing small-scale structure is considered. Lensing by both stars and a power law spectrum of density…
The Gaia second data release contains high-accuracy astrometric measurements of thousands of solar system bodies. These measurements raise the possibility of determining asteroid masses by modeling scattering events between massive objects…
The light deflection of one component of a binary system due to the gravitational field of the other component is investigated. While this relativistic effect has not been observed thus far, the question arises that whether this effect…
The Galactic center offers us a unique opportunity to test General Relativity (GR) with the orbits of stars around a supermassive black hole. Observations of these stars have been one of the great successes of adaptive optics on 8-10 m…
The microlensing of background stars by compact objects in globular clusters is analyzed. The main strength of the proposed search is the direct relationship between the lens mass and the time scale of the microlensing event. The main…
Gaia used a large sample of photometrically selected active galactic nuclei (AGNs) and quasars to remove the residual spin of its global proper motion system in order to achieve a maximally inertial reference frame. A small fraction of…
Due to the high efficiency of planet detections, current microlensing planet searches focus on high-magnification events. High-magnification events are sensitive to remote binary companions as well and thus a sample of wide-separation…
We employ differential astrometric methods to establish a small field reference frame stable at the micro-arcsecond ($\mu$as) level on short timescales using high-cadence simulated observations taken by Gaia in February 2017 of a bright…
Refined astrometry measurements allow us to detect large-scale deviations from isotropy through real-time observations of changes in the angular separation between sources at cosmic distances. This "cosmic parallax" effect is a powerful…
The time delays of gravitationally lensed quasars are generally believed to be unique numbers whose measurement is limited only by the quality of the light curves and the models for the contaminating contribution of gravitational…