PIPages
Labs

Benjamin Williams

University of Washington, WA·Astronomy & Astrophysics

The most massive stars live short, violent lives. At the end they shed material, explode as supernovae, and leave behind neutron stars or black holes.

Fields

Astronomy & Astrophysics

Physics

Topics

massive stars

stellar evolution

population synthesis

Grants
1 known grant, through Aug 2028

What they work on

  1. Measure delay time distributions, the time between star formation and the appearance of each object type, for Wolf-Rayet stars, stripped stars and supergiants in resolved Local Group galaxies.
  2. Measure formation efficiencies and timescales for X-ray binaries, systems where a neutron star or black hole feeds on a companion star, and for supernova remnants in nearby galaxies.
  3. Model each measured delay time distribution with COSMIC, a code that simulates populations of single and binary stars, to test predictions of massive-star evolution.
  4. Constrain mass-loss efficiency, the common envelope phase and supernova kicks by systematically comparing COSMIC predictions with the observed stellar populations.
  5. Develop tools to extract massive-star constraints from resolved stellar population data and object catalogs expected from the Vera C. Rubin Observatory.

More about the research

These final stages seed galaxies with energy and heavy elements, and they produce many of the bright transient events and gravitational-wave sources that astronomers detect. Yet theoretical models of these stars remain highly uncertain. Key unknowns include how much mass a star loses and how hard a newborn neutron star or black hole is kicked by its supernova.

Why it matters

Better limits on how massive stars lose mass, interact with companions and receive supernova kicks could sharpen predictions of where neutron stars, black holes and gravitational-wave sources come from, and of how much energy and how many heavy elements these stars return to galaxies. The analysis tools could also help astronomers extract more from upcoming Rubin Observatory star catalogs.

Known grants

From NIH and NSF research grants. Labs often have other funding we can't see.

Collaborative Research: Near Field Population Synthesis

NSF · Sep 2025 – Aug 2028

Closest labs

Christopher Kochanek

Ohio State University, OH·Astronomy & Astrophysics

Measure what fraction of massive-star core collapses fail and form a black hole without a supernova, by monitoring evolved stars in 27 nearby galaxies with the Large Binocular Telescope.

Douglas Gies

Georgia State University, GA·Astronomy & Astrophysics

Measure mass-loss rates of massive stars by comparing CHARA Array interferometric observations, which combine several telescopes for fine detail, at different wavelengths using the new SPICA visible-light instrument.

Kareem El-Badry

California Institute of Technology, CA·Astronomy & Astrophysics·Early-career

Measure how common post-interaction binary stars are across the Milky Way and estimate the mass distribution of black holes and neutron stars, using gaiamock software to correct for which binaries Gaia can detect.

The school

University of Washington: 81 labs on PI Pages, $1.7B a year on research, 694 research doctorates a year.

More about University of Washington

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