Reinhard Genzel investigates the central mass of the Milky Way using the motion of nearby stars. He coauthored the 2002 report led by Rainer Schödel that followed a close stellar orbit around Sagittarius A*.
An orbital path tests more than a high stellar speed: its curvature, timing and closest approach constrain how tightly the attracting mass is concentrated. The measured short-period orbit required several million solar masses in a compact central region, providing strong dynamical evidence for a supermassive black hole.[ref]
Closest Star Seen Orbiting the Supermassive Black Hole at the Centre of the Milky Way by Rainer Schödel and others. Author list and abstract: ten-year astrometry, Keplerian orbit and compact enclosed mass
Portrait of Reinhard Genzel
. MPE (Commons uploader HHgarching). CC BY-SA 3.0, via Wikimedia Commons. Source. Articles by others on the same topic
Reinhard Genzel is a German astrophysicist known for his work in the field of astrophysics, particularly in the study of supermassive black holes. He is one of the key figures behind the discovery of the supermassive black hole located at the center of the Milky Way galaxy, known as Sagittarius A*. Genzel shared the 2020 Nobel Prize in Physics with Roger Penrose and Andrea Ghez for their contributions to our understanding of black holes.