Stars and singularities: Stellar phenomena near a massive black hole

Abstract

This is a pedagogical review of recent results on the interactions of central massive black holes with stars very near them, focused on the black hole in the center of the Milky Way. Table of contents: [1] Introduction [2] Stellar dynamics near a black hole [2.1] Physical scales [2.2] A relaxed stellar system around a MBH [3] The stellar collider in the Galactic Center [3.1] The case for a dense stellar cusp in the Galactic Center [3.2] Tidal spin-up [3.3] Tidal scattering [4] The gravitational telescope in the Galactic Center [4.1] Gravitational lensing by a point mass [4.2] Pinpointing the MBH with lensed images [4.3] The detection of gravitational lensing [4.4] Magnification bias [4.5] Beyond the point mass lens approximation [5] Summary