Wendy Freedman | |
|---|---|
_(cropped)_2.jpg) Freedman in 2010 | |
| Born | (1957-07-17)July 17, 1957 (age 68) Toronto, Canada |
| Alma mater | University of Toronto (B.Sc. & Ph.D.) |
| Awards | Magellanic Premium (2002) Gruber Cosmology Prize (2009) Dannie Heineman Prize for Astrophysics (2016) Nature's 10 (2024) |
| Scientific career | |
| Institutions | Carnegie Observatories University of Chicago |
| Thesis | The Young Stellar Content of Nearby Resolved Galaxies[1] (1984) |
Wendy Laurel FreedmanFRS (born July 17, 1957) is a Canadian-American astronomer, best known for her measurement of theHubble constant, and as director of theCarnegie Observatories inPasadena, California, andLas Campanas, Chile. She is now the John & Marion Sullivan University Professor of Astronomy and Astrophysics at theUniversity of Chicago.[2] Her principal research interests are inobservational cosmology, focusing on measuring both the current and past expansion rates of the universe, and on understanding if there is missing physics in the standard (Lambda Cold Dark Matter) cosmological model.
In 2025,Time magazine listed her as one ofthe world's 100 most influential people.[3]
Freedman grew up in Toronto[4] in a Jewish family,[5] the daughter of a medical doctor and a concert pianist.[6] Her early interest in science was kindled by a formative high-school physics class. This led her to theUniversity of Toronto, where she was first abiophysics student, then an astronomy major, receiving her B.Sc. in 1979.[7] She remained at Toronto for her graduate work, receiving a Ph.D. in astronomy and astrophysics in 1984.[8] Joining the Carnegie Observatories in Pasadena, California, as a post-doctoral fellow in 1984, she became a faculty member of the scientific staff three years later as the first woman to join Carnegie's permanent staff. In 2003 she was named to the Crawford H. Greenewalt Chair and Director of Carnegie Observatories.[9] Freedman's early work was principally on theCepheid distance scale and the stellar populations of nearby galaxies.
Freedman was co-leader of an international team of 30 astronomers to carry out theHubble Space Telescope Key Project, a program aiming to establish the distance scale of the Universe and measure the current expansion rate, a quantity known as theHubble constant. This quantity determines the size of the visible universe and is key to determining its age. Over the course of the Key Project, the team measured the distances to 24 galaxies usingCepheid variable stars, and measured the Hubble constant using five independent methods. The project's researchers, led by Freedman, published their final result in 2001.[7][10] The work provided a value of the Hubble constant accurate to 10%, resolving a long-standing, factor-of-two debate.
She continues to refine her measurements of the Hubble constant using not just Cepheid variables but also the method of thetip of the red-giant branch.[11]
Freedman initiated theGiant Magellan Telescope (GMT) Project and served as chair of the board of directors from its inception in 2003 until 2015. GMT is an international consortium of leading universities and science institutions to build a 25-meter optical telescope at theCarnegie Institution for Science'sLas Campanas Observatory in the Chilean Andes. With a primary mirror 80 feet (24 meters) in diameter, the GMT is poised to be the world's second largest ground-based telescope when it is completed. The telescope, which has entered its construction phase and is expected to become fully operational by 2034, will be able to produce images 10 times sharper than those of the Hubble Space Telescope.
Freedman has been elected a member of the USNational Academy of Sciences,[12] theAmerican Philosophical Society,[13] theAmerican Academy of Arts and Sciences,[14] and a Fellow of theAmerican Physical Society[2] and a Legacy Fellow of the American Astronomical Society. She was electedFellow of the Royal Society in 2023.[15]
She has received several awards for her contributions to observational cosmology, including a Centennial Lectureship of the American Physical Society (1999), the John P. McGovern Award in Science (2000),[9] theMagellanic Premium Award of theAmerican Philosophical Society (2002)[16] and theMarc Aaronson Lectureship and prize (1994) "in recognition of a decade of fundamental contributions to the areas of the extra galactic distance scale and the stellar populations of galaxies".[17] In 2009 Freedman was one of three co-recipients of theGruber Cosmology Prize.[18] She received the 2016Dannie Heineman Prize for Astrophysics,[19] awarded jointly by theAmerican Institute of Physics and theAmerican Astronomical Society, "for her outstanding contributions and leadership role in using optical and infrared space- and ground-based observations of Cepheid stars, together with innovative analysis techniques, to greatly improve the accuracy of the cosmic distance scale and thereby constrain fundamental cosmological parameters."[20]
She was elected a Legacy Fellow of theAmerican Astronomical Society in 2020[21]
In 2024, she was included inNature's 10.[22]
In 2025, Freedman was a recipient of theNational Medal of Science.[23]
Asteroid107638 Wendyfreedman, discovered byDavid Healy at theJunk Bond Observatory in 2001, was named in her honor.[24] The officialnaming citation was published by theMinor Planet Center on 6 January 2007 (M.P.C. 58597).[25]
Freedman is married to longtime collaborator Barry F. Madore. They have two children.[6][26]
Media related toWendy Freedman at Wikimedia Commons
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