Related papers: Starspot induced effects in microlensing events wi…

We present results of numerical simulations of flux and linear polarization variations in transiting exoplanetary systems, caused by the host star disk symmetry breaking. We consider different configurations of planetary transits depending…

This study explores photometric variability in a sample of hot stars in order to test whether variability arises from rotational modulation due to surface temperature spots. Frequencies determined from the projected rotational velocities…

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…

In this article we review the astrophysical application of gravitational microlensing. After introducing the history of gravitational lensing, we present the key equations and concept of microlensing. The most frequent microlensing events…

At present, microlensing light curves from different telescopes and filters are photometrically aligned by fitting them to a common model. We present a second method based on photometry of common field stars. If two spectral responses are…

I investigate the effects of source clustering on the weak lensing statistics, more particularly on the statistical properties of the local convergence, kappa, at large angular scales. The Perturbation Theory approach shows that the…

Light curves of microlensing events involving stellar binaries and planetary systems can provide information about the orbital elements of the system due to orbital modulations of the caustic structure. Accurately measuring the orbit in…

Stellar activity features such as spots can create complications in determining planetary parameters through spectroscopic and photometric observations. The overlap of a transiting planet and a stellar spot, for instance, can produce…

We investigate high-magnification events caused by wide binary stellar and planetary systems under the moderately strong finite-source effect where the diameter of the source star is comparable with the caustics induced by a binary…

We describe new scenarios of generating curvature perturbations when inflaton (curvaton) has significant interactions. We consider a ``spot'', which arises from interactions associated with enhanced symmetric point (ESP) on the trajectory.…

Gravitational lensing by spinning stars, approximated as homogeneous spheres, is discussed in the weak field limit. Dragging of inertial frames, induced by angular momentum of the deflector, breaks spherical symmetry. I examine how the…

Stellar magnetic activity is a source of noise in the study of the transits of extrasolar planets. It induces flux variations which affect significantly the transit depth determination and the derivations of planetary and stellar…

We investigate the effect of a single microlens on Stokes parameters. Semi-analytical formulae of the microlensed Stokes parameters are derived. The formulae not only reduce the double integrals in the estimations of those quantities but…

For 30 years, cyclical wind variability in OB stars has puzzled the astronomical community. Phenomenological models involving co-rotating bright spots provide a potential explanation for the observed variations, but the underlying physics…

For microlenses with sufficiently low mass, the angular radius of the source star can be much larger than the angular Einstein ring radius of the lens. For such extreme finite source effect (EFSE) events, finite source effects dominate…

We calculate the effects of spot size on pulse profiles of moderately rotating neutron stars. Specifically, we quantify the bias introduced in radius measurements from the common assumption that spots are infinitesimally small. We find that…

We describe a real-time spectroscopic program to observe bright gravitational microlensing events toward the Galactic Bulge. The program is carried out using the NTT at ESO. We present the preliminary analysis of the microlensing events we…

We investigate the impact of starspots on the evolution of late-type stars during the pre-main sequence (pre-MS). We find that heavy spot coverage increases the radii of stars by 4-10%, consistent with inflation factors in eclipsing binary…

Many active stars are covered in spots, much more so than the Sun, as indicated by spectroscopic and photometric observations. It has been predicted that star spots induce non-zero intrinsic linear polarization by breaking the visible…

We present the details of the Bayesian analysis on the planetary microlensing event MOA-2016-BLG-227, whose excess flux is likely due to a source/lens companion or an unrelated ambient star, as well as of the assumed prior distributions.…