Andrea M. Ghez

Lore & Background

Ghez was born in New York City to Susanne and Gilbert Ghez. Her father, of Jewish heritage, was born in Rome, Italy, to a family originally from Tunisia and Frankfurt, Germany; her mother was from an Irish Catholic family from North Attleborough, Massachusetts. In 1969, her father completed his Ph.D. at Columbia University and accepted a position at the University of Chicago, where Ghez attended the Laboratory School. The Apollo program Moon landings inspired her to aspire to be the first female astronaut, and her mother encouraged that goal by purchasing a telescope. Her most influential female role model was her high school chemistry teacher. She began college majoring in mathematics, then changed to physics, receiving a BS in physics from MIT in 1987 and a PhD under Gerry Neugebauer at Caltech in 1992.

Ghez's research employs high spatial resolution imaging techniques, such as the adaptive optics system at the Keck telescopes, to study star-forming regions and the supermassive black hole at the center of the Milky Way known as Sagittarius A*. By imaging the Galactic Center at infrared wavelengths, she and her colleagues peered through heavy dust to reveal images of the center of the Milky Way. They followed the orbits of stars around the black hole, including the star S2, which has made a complete elliptical orbit since detailed observations began in 1995. In October 2012, her team identified a second star, S0-102, orbiting the Galactic Center. Using Kepler's third law, they showed that the mass of Sgr A* is 4.1±0.6 million solar masses.

Reader's Guide

Andrea Ghez's significance lies in her pioneering use of high-resolution infrared imaging and adaptive optics to provide the most compelling evidence for a supermassive black hole at the center of the Milky Way. By tracking the orbits of stars around Sagittarius A*, she and her team demonstrated that a compact object of about 4 million solar masses governs their motion, a discovery that earned her a share of the 2020 Nobel Prize in Physics. Her work has made the Galactic Center one of the best demonstrated cases for a supermassive black hole, and it continues to provide a testbed for general relativity. Ghez is also notable as the fourth woman to win the Nobel Prize in Physics, following Marie Curie, Maria Goeppert Mayer, and Donna Strickland. Beyond her research, she has contributed to public science communication through television documentaries, a TED talk, and the book 'You Can Be a Woman Astronomer,' co-authored with Judith Love Cohen.

Did You Know?

• Ghez was the fourth woman to win the Nobel Prize in Physics, after Marie Curie (1903), Maria Goeppert Mayer (1963), and Donna Strickland (2018).
• She co-authored the book 'You Can Be a Woman Astronomer' with Judith Love Cohen.
• In 2000, Discover magazine listed Ghez as one of 20 promising young American scientists in their respective fields.
• She is an active swimmer in the UCLA Masters Swim Club.

Piercing the Dust: Tracking Stars Around Sagittarius A*

From her position as the Lauren B. Leichtman and Arthur E. Levine chair in Astrophysics at UCLA, Ghez has devoted her career to peering into the heart of the Milky Way. Her central research strategy involves high spatial resolution imaging at infrared wavelengths, a technique that lets light penetrate the thick dust clouds blocking visible observations of the galactic center. Working with the 10-meter W.M. Keck Telescope and its adaptive optics system to correct for atmospheric turbulence, she and her colleagues achieved the resolution needed to track individual stars orbiting Sagittarius A*. Since 1995, the team has followed the partial orbits of numerous stars, with the star S2 completing a full elliptical revolution. In October 2012, her group identified another star, S0-102, in the same region. By applying Kepler's third law to these orbital motions, Ghez's team calculated the mass of Sgr A* at 4.1 plus or minus 0.6 million solar masses. Because the galactic center lies roughly one hundred times closer than the next nearest supermassive black hole in M31, this makes it one of the most compelling cases for such an object.

The 2020 Nobel and a Milestone for Women in Physics

The 2020 Nobel Prize in Physics marked the culmination of decades of painstaking observation. Ghez shared the award with Reinhard Genzel, the two receiving one half of the prize for demonstrating that a supermassive compact object—now widely understood to be a black hole—governs the orbits of stars at the center of our galaxy. The other half went to Roger Penrose for his theoretical work on black hole formation. In accepting this honor, Ghez became only the fourth woman ever to receive the physics Nobel, joining a remarkably short list that includes Marie Curie in 1903, Maria Goeppert Mayer in 1963, and Donna Strickland in 2018. The prize recognized work that began with early infrared imaging of the galactic center and matured into the precise orbital tracking of stars like S2 and S0-102, measurements that left little doubt about the nature of the invisible mass anchoring the Milky Way. For Ghez, the Nobel validated a research program built on patience, resolution, and the quiet accumulation of positional data over many years.

A Childhood Shaped by Two Worlds and the Moon

Born in New York City on June 16, 1965, Andrea Mia Ghez grew up in a household shaped by two distinct cultural heritages. Her father, Gilbert, was of Jewish descent, born in Rome to a family with roots in Tunisia and Frankfurt, Germany, while her mother, Susanne, came from an Irish Catholic family in North Attleborough, Massachusetts. In 1969, Gilbert completed his doctorate at Columbia University and took a faculty position at the University of Chicago, where young Andrea attended the university's Laboratory School. The Apollo Moon landings left a lasting impression on her, sparking a childhood ambition to become the first female astronaut. Her mother nurtured that curiosity by purchasing a telescope. Looking back, Ghez has identified her high school chemistry teacher as her most influential female role model. She initially enrolled in college intending to study mathematics before switching to physics, earning her bachelor's degree from MIT in 1987. She went on to complete her doctorate at the California Institute of Technology in 1992 under the supervision of Gerry Neugebauer.

Recognition, Advocacy, and Reaching Beyond the Observatory

Beyond the research program, Ghez has built a broad public profile as a science communicator and advocate for women in STEM. She has appeared in television documentaries produced by the BBC, Discovery Channel, and The History Channel, and featured in a 2006 episode of the PBS series Nova. The My Hero Project recognized her as a Science Hero, and in 2000 Discover magazine named her among twenty promising young American scientists. In 2019, she co-authored the book You Can Be a Woman Astronomer with Judith Love Cohen, a work aimed at encouraging the next generation. Her institutional recognition is extensive: elected to the National Academy of Sciences in 2004, the American Philosophical Society in 2012, and made a Fellow of the American Physical Society in 2019. Her honors include the MacArthur Fellowship, the Crafoord Prize in Astronomy, the Royal Society Bakerian Medal, and an honorary doctorate from the University of Oxford. In 2020, the American Astronomical Society named her a Legacy Fellow, capping a career that has consistently bridged frontier research with public engagement.