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1965–

Andrea Ghez

Andrea Ghez led infrared stellar-orbit studies of the Galactic centre, using precise observations to investigate the Milky Way’s compact central mass.

United States New York, NY, USA Updated 8 November 2026
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In this biography

Quick facts

Born
16 June 1965
Birthplace
New York, NY, USA
Nationality
Not independently established
Known for
Tracking stellar orbits to investigate the Milky Way’s compact central mass

Why this life matters

Tracking stellar orbits to investigate the Milky Way’s compact central mass

Timeline

Key moments

  1. Birth

    Andrea Ghez was born in New York, NY, USA.

  2. Stellar-orbit paper

    Published the refereed study corresponding to the 2003 Galactic-centre orbit preprint.

  3. Nobel recognition

    Received Nobel recognition for the work described in the official award record.

Physics training and infrared astronomy

Andrea Ghez was born in New York City in 1965. She earned a physics bachelor’s degree at MIT in 1987 and a doctorate at Caltech in 1992. A Hubble fellowship at the University of Arizona preceded her 1994 appointment at UCLA. Her institutional CV records the progression through faculty ranks and a research programme in high-resolution astronomy. This training combined physical interpretation with demanding observations, preparing her to study regions where ordinary visible-light images could not reveal the required stellar detail.

Sources for this section: [4] · [1]

Following stars through the dust

The Galactic centre is heavily obscured in visible light. Ghez’s group used near-infrared observations and high-resolution techniques at the Keck telescopes in Hawaii to track individual stars. Repeated positions transformed a crowded field into a time-dependent measurement problem. UCLA’s research explanation distinguishes this programme from the independent European group associated with Reinhard Genzel. The groups’ observations were not photographs of an event horizon; they used nearby stellar motion to investigate a mass concentration that could not be assessed from brightness alone.

Sources for this section: [3] · [2]

Turning orbits into mass evidence

Ghez and collaborators including Samir Salim, Seth Hornstein, Angelle Tanner, Jessica Lu, Mark Morris, Eric Becklin and Gaspard Duchêne analysed individual stellar orbits around the central source. A 2003 preprint became a 2005 Astrophysical Journal paper. Orbit information constrained both the enclosed mass and the compact region containing it. The result was more specific than merely finding fast stars: the time-dependent trajectories made the central gravitational explanation testable. Values in that historical paper should not be presented as unchanged present-day precision measurements.

Sources for this section: [2] · [1]

Recognition and an observational legacy

Ghez shared the 2020 Nobel Prize in Physics with Genzel and Roger Penrose; her part recognised the discovery of a supermassive compact object at the Galaxy’s centre. Her CV also records later work on distance, orbital properties and relativistic effects. The central achievement depended on repeated observations, instrumentation and collaboration over many years. Its value lies in making a difficult inference progressively tighter: visible stars supplied a way to investigate an unseen gravitational source, with the observed region and the mass concentration constrained together.

Sources for this section: [4] · [1] · [3]

Quick answers

Frequently asked questions about Andrea Ghez

When did Ghez join UCLA?
In 1994, after a Hubble fellowship at the University of Arizona.
Was the 2020 prize for an event-horizon image?
No. Her award concerned discovery of the supermassive compact object through Galactic-centre studies.

Keep exploring

Lives connected to this story

Sources and further reading

Explore the evidence

These references support the biography and offer further reading. Official records, first-person accounts and independent reporting provide different perspectives; image records document attribution and licensing.

  1. 1. UCLA; internally dated 31 January 2025Andrea M. Ghez — Curriculum Vitae

    The PDF filename contains 2024, but the actual document header states updated 31 January 2025.

  2. 2. Ghez and colleagues;2003 preprint, 2005 ApJ publicationStellar Orbits Around the Galactic Center Black Hole

    The 2003 preprint and 2005 journal article are the same research work, not independent evidence or separate copyright allowances.

  3. 3. UCLA Galactic Center GroupJourney to the Center of the Milky Way
  4. 4. Nobel Prize OutreachAndrea Ghez — Facts
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