Keivan Stassun
Stevenson Professor of Physics and Astronomy | Vanderbilt University
Nashville, TN, UNITED STATES
Expert in the search for Earth-like planets across the galaxy and an advocate for diversity, including neurodiversity, in the academy.
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Biography
The research of Keivan Stassun seeks to address questions related to the formation of stars and planetary systems. With the advent of all-sky surveys, large-format detectors, and high-performance computers, this work increasingly involves approaches at the interface of astronomy, physics, computer science, and informatics.
After earning A.B. degrees in physics and astronomy from UC Berkeley, and the PhD in astrophysics from the University of Wisconsin, Stassun was a NASA Hubble postdoctoral fellow before joining the Vanderbilt faculty in 2003. A recipient of a CAREER award from NSF and a Cottrell Scholar Award from the Research Corporation for Science Advancement, Stassun’s research on stars and exoplanets has appeared in more than 500 peer-reviewed journal articles. He is a co-investigator for the NASA Transiting Exoplanet Survey Satellite (TESS) mission and chairs the executive committee of the Sloan Digital Sky Survey. From 2004 to 2015, he served as founding director of the Fisk-Vanderbilt Masters-to-PhD Bridge Program, which has become one of the nation’s top producers of PhDs to underrepresented minorities in the physical sciences. To date, he has mentored 30 PhD dissertations in astronomy and astrophysics and placed more than 20 PhDs into academic research careers. He has served on the federal Astronomy and Astrophysics Advisory Committee, the NSF Committee for Equal Opportunity in Science and Engineering, is a recipient of the American Physical Society’s Nicholson Medal for Human Outreach, and is an elected Fellow of the American Physical Society, American Astronomical Society, and American Association for the Advancement of Science. He has served as an expert witness to the US House of Representatives Committee on Science and Technology. For the past ten years, Stassun has served as founding director of the Vanderbilt Initiative in Data-intensive Astrophysics. In 2017, Stassun launched the Center for Autism & Innovation, focused on advancing science and engineering through the engagement and advancement of individuals with autism. The Center has become permanently endowed by a $10 million gift from Frist Family Foundation. Most recently, Stassun was selected for a $1 million HHMI Professor award, was named Mentor of the Year by the AAAS, was honored by the White House with a Presidential Award for Excellence in Science and Engineering Mentoring, and served on the National Academies’ Decadal Steering Committee for Astronomy & Astrophysics.
Areas of Expertise (9)
Star Formation
Planet Formation
Astronomy
Planetary Systems
Astronomical Phenomena
Stars
Neurodiversity
Physics
Exoplanets
Accomplishments (5)
National Medal of Science (professional)
2025-01-03
The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral and social sciences, biology, chemistry, engineering, mathematics and physics. The twelve member presidential Committee on the National Medal of Science is responsible for selecting award recipients and is administered by the National Science Foundation (NSF).
MacArthur Fellow (professional)
2024-10-01
The MacArthur Fellowship is a $800,000, no-strings-attached award to extraordinarily talented and creative individuals as an investment in their potential.
Legacy Fellow of the American Astronomical Society (professional)
2020-01-01
The AAS Fellows program recognizes AAS members for their contributions toward the Society's mission of enhancing and sharing humanity's scientific understanding of the universe. Fellows may be cited for original research and publication, innovative contributions to astronomical techniques or instrumentation, significant contributions to education and public outreach, and noteworthy service to astronomy and to the Society itself.
Research Corporation for Science Advancement IMPACT Award (professional)
2019-01-01
The Research Corporation for Science and Advancement IMPACT Award recognizes the work of an outstanding Cottrell Scholar who has had a national impact in science through leadership and service activities.
Presidential Award for Excellence in Science, Math, and Engineering Mentoring (professional)
2018-01-01
The Presidential Award for Excellence in Science, Math, and Engineering Mentoring is a prestigious award given by the White House to individuals and organizations that demonstrate exceptional commitment to mentoring students from underrepresented groups in STEM fields, recognizing their significant contributions to expanding diversity within the science, mathematics, and engineering workforce; it is administered by the National Science Foundation (NSF).
Education (3)
University of Wisconsin-Madison: Hubble Postdoc, Astronomy 2003
University of Wisconsin-Madison: Ph.D, Astronomy 2000
UC Berkeley: B.A., Physics 1994
Links (3)
Selected Media Appearances (10)
Vanderbilt professor Keivan Stassun receives prestigious $800K MacArthur fellowship grant
Tennessean online
2024-10-01
Vanderbilt University professor and astronomer Keivan Stassun was named among the 2024 MacArthur Fellows, a prestigious honor that comes with an $800,000 grant that each fellow can spend however they see fit.
Astronomy Discoveries at Vanderbilt
NewsChannel 5 online
2023-08-24
Did you know that groundbreaking astronomy discoveries are being made right here in Nashville? On this episode of MorningLine, Nick Beres is joined by Stephen Taylor and Keivan Stassun, Physics and Astronomy Professors at Vanderbilt University, to discuss their work and talk about space.
Peering into space with Nashville astronomers
WPLN radio
2023-07-21
Some of the most exciting research in astronomy is happening right here in Nashville. A little more than a year ago, NASA released the first images from the James Webb Space Telescope. One of the first approved studies using this imagery was led by Vanderbilt professor Keivan Stassun, who is searching for Earth-like planets with NASA’s TESS Exoplanet Mission. And just weeks ago, a groundbreaking study demonstrating how gravitational waves permeate the universe was published by a team led by another Vanderbilt astrophysicist, Stephen Taylor.
Want to see the total eclipse in 2024? Better make your plans now.
The Washington Post online
2023-04-28
Most of the country will see at least a partial eclipse from wherever they are. That experience is “neat — as in, your kids will say, yeah that was pretty cool,” Keivan Stassun, a professor of physics and astronomy at Vanderbilt University, said in an email, but viewing a total solar eclipse is “a life event.”
First images from NASA’s James Webb Telescope will be shared with researchers and students in Middle Tennessee
WPLN radio
2022-07-12
Dr. Keivan Stassun, an astrophysicist at Vanderbilt University, is helping lead that effort. He and his team will analyze these new images for revelations about space and time in distant galaxies.
NASA Needs 'Multi-generational Commitment' for Space Mission DEI: Report
Newsweek online
2022-05-18
Keivan Stassun, one of the study's co-authors and the Stevenson Professor of Physics & Astronomy at Vanderbilt University's College of Arts & Science, added in a Vanderbilt news release that SMD's current process can "systematically disadvantage and exclude folks of certain backgrounds or life experiences who could be superb, arguably even more capable, leaders."
Fix the system, not the students
Science online
2022-03-02
Even before the TEAM-UP report, some academic physicists had begun to take similar steps. At Vanderbilt University, astrophysicist Keivan Stassun was moved to act by data showing Black undergraduates are being pushed out of the field they want to study.
NASA’s biggest telescope is about to launch, and a Vanderbilt astronomer has a ‘front row seat’ to cosmic discovery
WPLN radio
2021-12-23
“The James Webb Telescope is by far, by a country mile, the single most ambitious and technologically-advanced thing that human beings have sent into space,” said Dr. Keivan Stassun, an astrophysicist at Vanderbilt University.
Recruiting for talent on the autism spectrum
CBS 60 Minutes tv
2021-07-18
Dan Burger's unique abilities caught the attention of Keivan Stassun, an astrophysics professor at Vanderbilt. His son is on the autism spectrum, and Stassun helped start the Frist Center.
Revealed: The ‘Next Hubble’ Space Telescope That Will Photograph Another Earth, Cost $11 Billion And Launch In The 2040s
Forbes online
2021-11-04
The plans involve a new flagship space telescope, but rather than selecting one of the four proposals on offer the report has opted for a mix of two of them. “We did not want to say what mission concept we like best, but instead we wanted to say what we need to achieve,” said Keivan Stassun of Vanderbilt University and one of the members of the steering committee for this report.
Selected Articles (3)
Two Young Eclipsing Binaries in Orion with Temperatures and Radii Affected by Spots and Third Bodies
The Astronomical JournalMarina Kounkel, Keivan G. Stassun
2024-09-01
In this work we present a model of two young eclipsing binaries in the Orion complex. Both heavily spotted, they present radii and temperatures that are in disagreement with the predictions of standard stellar models. 2M05‑06 consists of two stars with different masses (∼0.52 and ∼0.42 M ⊙) but with very similar radii (∼0.9 R ⊙), and with the less massive star having a highly spotted surface that causes it to have a hotter (unspotted) photosphere than the higher-mass star. The other system, 2M05‑00, consists of two stars of very similar masses (∼0.34 M ⊙), but very different radii (∼0.7 and ∼1.0 R ⊙), which creates an appearance of the two eclipsing stars being noncoeval. 2M05‑00 appears to have a tertiary companion that could offer an explanation for the unusual properties of the eclipsing stars, as has been seen in some other young triple systems. Comparing the empirically measured properties of these eclipsing binaries to the predictions of stellar models, both standard and magnetic, we find that only the magnetic models correctly predict the observed relationship between mass and effective temperature. However, standard (nonmagnetic) models better predict the temperatures of the unspotted photospheres. These observations represent an important step in improving our understanding of pre-main-sequence stellar evolution and the roles of spots and tertiaries on fundamental stellar properties.
The Evolution of Stellar X-Ray Activity and Angular Momentum as Seen by eROSITA, TESS, and Gaia
The Astrophysical JournalKeivan G. Stassun, Marina Kounkel
2024-06-01
We have assembled a sample of ∼8200 stars with spectral types F5V–M5V, all having directly measured X-ray luminosities from eROSITA and rotation periods from TESS and having empirically estimated ages via their membership in stellar clusters and groups identified in Gaia astrometry (ages 3–500 Myr). This is the largest such study sample yet assembled for the purpose of empirically constraining the evolution of rotationally driven stellar X-ray activity. We observe rotation–age–activity correlations that are qualitatively as expected: stars of a given spectral type spin down with age, and they become less X-ray active as they do so. We provide simple functional representations of these empirical relationships that predict X-ray luminosity from basic observables to within 0.3 dex. Interestingly, we find that the rotation–activity relationship is far simpler and more monotonic in form when expressed in terms of stellar angular momentum instead of rotation period. We discuss how this finding may relate to the long-established idea that rotation–activity relationships are mediated by stellar structure (e.g., convective turnover time, surface area). Finally, we provide an empirical relation that predicts stellar angular momentum from basic observables, without requiring a direct measurement of stellar rotation, to within 0.5 dex.
Detecting New Visual Binaries in Gaia DR3 with Gaia and Two Micron All Sky Survey (2MASS) Photometry. II. Speckle Observations of 16 Low-separation Systems
The Astronomical JournalIlija Medan, Sébastién Lépine, Zachary Hartman, Keivan G. Stassun
2024-06-01
Here we present speckle observations of 16 low-separation (s < 30 au) high-probability candidate binaries from the catalog by Medan et al., where secondaries typically lack astrometric solutions in Gaia. From these speckle observations, we find a second component is always detected within the field of view. To determine if the detection is consistent with a physical companion or a chance alignment with a background source, we utilize a statistic from Tokovinin & Kiyaeva that compares the apparent motion of the systems to the expected orbital motion ( μ′ ). Using simulated binary orbits, we construct likelihood distributions of μ′ assuming various total errors on the measurements. With the hypothesis that the system is a true binary, we show that large measurement errors can result in μ′ values higher than expected for bound systems. Using simulated chance alignments, we also create similar likelihoods to test this alternative hypothesis. By combining likelihoods of both true binaries and chance alignments, we find that 15 of the 16 candidates are physical systems regardless of the level of measurement error. Our findings also accommodate all 16 as physical systems if the average, relative measurement error on the binary separations and position angles is ∼4.3%, which is consistent with our knowledge of the Gaia and Gemini speckle pipelines. Importantly, beyond assessing the likelihood of a true binary versus chance alignment, this quantitative assessment of the true average measurement error will allow more robust error estimates of mass determinations from short separation binaries with Gaia and/or Gemini speckle data.
