Related papers: Microlensing extended stellar sources
One possibility for detecting low-amplitude pulsational variations is through gravitational microlensing. During a microlensing event, the temporary brightness increase leads to improvement in the signal-to-noise ratio, and thereby better…
We prove a gravitational lensing theorem: the magnification of a source of uniform brightness by a foreground spherical lens is mu =1+pi(2R_E^2-R_L^2)/A, where A is the area of the source and R_E and R_L are the Einstein radius and size of…
Microlensing of stars in strongly lensed galaxies can lead to temporary extreme magnification factors ($\mu\!>\!1000$), enabling their detection at high redshifts. Following the discovery of Icarus, several stars at cosmological distances…
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…
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…
We calculate the magnification light curves due to stellar microlensing of gamma-ray burst (GRB) afterglows. A GRB source appears on the sky as a thin ring which expands faster than the speed of light and is maximally magnified as it…
Variability observed in photometric lightcurves of late-type stars (on timescales longer than a day) is a dominant noise source in exoplanet surveys and results predominantly from surface manifestations of stellar magnetic activity, namely…
We present the results of numerical experiments to assess degeneracies in lightcurve models of starspots. Using synthetic lightcurves generated with the Cheetah starspot modeling code, we explore the extent to which photometric light curves…
We present a novel technique to determine the absolute inclination of single stars using multi-wavelength sub-milliarcsecond astrometry. The technique exploits the effect of gravity darkening, which causes a wavelength-dependent astrometric…
The light curve of an exoplanetary transit can be used to estimate the planetary radius and other parameters of interest. Because accurate parameter estimation is a non-analytic and computationally intensive problem, it is often useful to…
The most important uncertainty in the results of gravitational microlensing experiments comes from the difficulties of photometry caused by blending of source stars. Recently Nemiroff (1997) pointed out that the results of microlensing…
Diffraction is important when nearby substellar objects gravitationally lens distant stars. If the wavelength of the observation is comparable to the Schwarzschild radius of lensing object, diffraction leaves an observable imprint on the…
Astrometric observations of microlensing events were originally proposed to determine the lens proper motion with which the physical parameters of lenses can be better constrained. In this proceeding, we demonstrate that besides this…
Microlensing surveys have proven to be tremendously fruitful in providing valuable data products for many fields of astrophysics, from eclipse lightcurves for substellar candidates to limb darkening in stellar atmospheres. We report on a…
In general, in the studies of transit light-curves and the Rossiter-McLaughlin (RM), the contribution of the planet's gravitational microlensing is neglected. Theoretical studies, have, however shown that the planet's microlensing can…
In the process of analyzing an observed light curve, one often confronts various scenarios that can mimic the planetary signals causing difficulties in the accurate interpretation of the lens system. In this paper, we present the analysis…
Microturbulence (\xi) is a key parameter introduced in stellar spectroscopy to explain the strength of saturated lines by formally incorporating an additional thermal broadening term in the line opacity profile. Although our Sun can serve…
Under the current microlensing planet search strategy of monitoring events caused by stellar-mass lenses, only planets located within a narrow region of separations from central stars can be effectively detected. However, with the dramatic…
We investigate the effects of stellar limb-darkening and photospheric perturbations for the onset of wind structure arising from the strong, intrinsic line-deshadowing instability (LDI) of a line-driven stellar wind. A linear perturbation…
The gravitational microlensing light curves that reveal the presence of extrasolar planets generally yield the planet-star mass ratio and separation in units of the Einstein ring radius. The microlensing method does not require the…