Dr. Andrea Ghez
Nobel Laureate, Physics 2020
Alpheus Smith Lecture
Open to the Public
"From the Possibility to the Certainty of a Supermassive Black Hole"
Thursday, September 25th, 2025
Location: TBA
Abstract: Learn about new developments in the study of supermassive black holes. Through the capture and analysis of twenty years of high-resolution imaging, the UCLA Galactic Center Group has moved the case for a supermassive black hole at the center of our galaxy from a possibility to a certainty and provided the best evidence to date for the existence of these truly exotic objects. This was made possible with the first measurements of stellar orbits around a galactic nucleus. Further advances in state-of-the-art of high-resolution imaging technology on the world’s largest telescopes have greatly expanded the power of using stellar orbits to study black holes. Recent observations have revealed an environment around the black hole that is quite unexpected (young stars where there should be none; a lack of old stars where there should be many; and a puzzling new class of objects). Continued measurements of the motions of stars have solved many of the puzzles posed by these perplexing populations of stars. This work is providing insight into how black holes grow and the role that they play in regulating the growth of their host galaxies. Measurements this past year of stellar orbits at the Galactic Center have provided new insight on how gravity works near a supermassive hole, a new and unexplored regime for this fundamental force of nature.
Bio: Andrea M. Ghez, professor of Physics & Astronomy at UCLA and the Lauren B. Leichtman & Arthur E. Levine chair in Astrophysics, is one of the world’s leading experts in observational astrophysics and is director of UCLA’s Galactic Center Group.
In 2020, she became the fourth woman to be awarded the Nobel Prize in Physics for her discovery of a massive black hole in the center of our galaxy -- Milky Way. This work established, beyond a shadow of a doubt, the existence of these exotic objects, which challenge our understanding of fundamental physics and astronomy. Furthermore her work has opened a new approach to studying massive black holes and she is currently focused on using this approach to understand both the physics of how gravity works and the role that black holes play in the formation and evolution of galaxies.
She serves on several leadership committees for the advancement of science within the US, the UC-system, the W.M. Keck Observatory in Hawaii (which hosts the largest telescopes in the world and is critical to her work), and the future Thirty Meter Telescope, an international collaboration between the US, Canada, Japan, and India. In 2025, she joined the board of the W. M. Keck Foundation.
Professor Ghez is also very committed to the communication of science to the general public and inspiring young girls to enter the field of science.
She earned her B.S. from MIT in 1987 and her PhD from Caltech in 1992 and has been on the faculty at UCLA since 1994. Beyond the Nobel she has won numerous awards, including the 2025 Rumford Prize from the American Academy of Arts & Sciences (established in 1796; one of the oldest scientific prizes in the United States), 2016 Bakerian Medal from the Royal Society of London, 2012 Crafoord Prize in Astronomy from the Royal Swedish Academy of Science, where she is the first woman to win this prize in any field.