Robert Mathieu
University of Wisconsin-Madison, WI·Astronomy & Astrophysics
Most stars, more than 95 percent of them, will end their lives as white dwarfs. A white dwarf is the dense leftover core of a star that has used up its nuclear fuel; it holds about the Sun's mass in a body roughly the size of Earth.
- Fields
Astronomy & Astrophysics
Physics
- Topics
white dwarfs
binary stars
mass transfer
- Grants
- 1 known grant, through Aug 2027
What they work on
- Build the APOGEE-GALEX-Gaia Catalog, a sample of thousands of white dwarf binaries that have exchanged mass, by combining infrared APOGEE spectra with GALEX ultraviolet data and Gaia data.
- Characterize the composition of these interacting binaries and the amount of mass they share, using observations across a wide range of wavelengths.
- Map how the properties of post-mass-transfer white dwarf binaries change as the companion star ages, from the main sequence through the subgiant, red giant and red clump stages.
- Improve understanding of how stars exchange mass, including common envelope evolution, Roche lobe overflow, wind accretion, mass stripping and mergers, using the population revealed by the catalog.
More about the research
Many white dwarfs orbit a partner star closely enough for the two to swap material. That exchange changes how both stars are built and how they age afterward. These pairs are useful for studying the final stages of a star's life. They can also be used to trace the motions of the Milky Way, and they may produce gravitational waves.
Why it matters
This work adds basic knowledge about how stars age when they are part of a pair. It will provide a catalog of thousands of white dwarf binaries for other researchers to use. Because these systems trace the dynamics of the Milky Way and may emit gravitational waves, the catalog could also inform studies of galaxy structure and gravitational-wave sources. In addition, the project is building astronomy training programs for blind and visually impaired learners.
Known grants
From NIH and NSF research grants. Labs often have other funding we can't see.
Closest labs
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.
Andrew Mann
University of North Carolina at Chapel Hill, NC·Astronomy & Astrophysics·Early-career
Measure luminosity, radius, mass and age to better than 5% accuracy for 5–500 million-year-old K and M stars by analyzing light curves of eclipsing and astrometric binaries found by Gaia, K2 and TESS.
Benjamin Williams
University of Washington, WA·Astronomy & Astrophysics
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.
The school
University of Wisconsin-Madison: 91 labs on PI Pages, $1.9B a year on research, 854 research doctorates a year.
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