SgrA Black Hole Stellar Orbit Explorer

Live Script illustrating fits to observations of stars orbiting the black hole in the center of the Milky Way.

Observations and analysis of motions of stars around the black hole at the center of the Milky Way galaxy were the basis for the 2020 Nobel Prize in Physics awarded to Reinhard Genzel and Andrea Ghez. The observations include the angular positions of target stars relative to reference stars from high-resolution infrared imaging and the velocity along the line of sight at various times using Doppler spectroscopy. For most of these stars, only a fraction of an orbit has been observed. A challenge is to fully reconstruct the orbits in three dimensions, each described by seven orbital elements, from limited observations.

This educational Live Script compares angular and radial velocity observational data to professional fit results for numerous stars with visualizations that bring the data to life. A refined fit is used to extract the estimates of the mass of the black hole star by star. The script may interest students and instructors of physics and astronomy especially. A related script [1] provides additional information, a simulation of observations, and an example of the fitting procedure in general use. Additional educational Live Scripts by the author may be found here.