The Physics Society of Iran Iranian Journal of Physics Research 1682-6957 20 3 2020 11 21 Limb-darkening effect of source stars in gravitational microlensing observations in different filters Limb-darkening effect of source stars in gravitational microlensing observations in different filters 495 500 1642 10.47176/ijpr.20.3.71096 FA P Sangtarash Department of Physics, Isfahan University of Technology, Isfahan, Iran Sedigheh Sajadiyan Physics Department. IUT. Isfahan. Iran Journal Article 2020 07 25 Spherical property of stars means that the flux received from different parts of their surface is not uniform and less than its center at the edges. Thus, the edges appear darker than the center of the star; this is called the limb-darkening effect. The amount of the limb-darkening effect depends on the stellar atmosphere, stellar temperature, gravity and metallicity. In this paper, we offer a method to  better characterize  the source stars in high-magnification microlensing events. In high-magnification microlensing events in  which the lens is transiting the source surface, the  non-uniformity of the stellar flux and the magnification factor as a function of the lens location can both cause the stellar color changes with time. Measuring the stellar color while lens is crossing the source surface will offer additional  information regarding  the dependence of the limb-darkening parameters on  the wave length and hence, the stellar atmosphere parameters and the source star parameters. Spherical property of stars means that the flux received from different parts of their surface is not uniform and less than its center at the edges. Thus, the edges appear darker than the center of the star; this is called the limb-darkening effect. The amount of the limb-darkening effect depends on the stellar atmosphere, stellar temperature, gravity and metallicity. In this paper, we offer a method to  better characterize  the source stars in high-magnification microlensing events. In high-magnification microlensing events in  which the lens is transiting the source surface, the  non-uniformity of the stellar flux and the magnification factor as a function of the lens location can both cause the stellar color changes with time. Measuring the stellar color while lens is crossing the source surface will offer additional  information regarding  the dependence of the limb-darkening parameters on  the wave length and hence, the stellar atmosphere parameters and the source star parameters. https://ijpr.iut.ac.ir/article_1642_81c650caac28cdefce4de5ddc18befa0.pdf