Libbrecht has built a telescope designed to measure velocities on the Sun with very high accuracy. From the spatial and temporal velocity patterns he deduces the precise frequencies of the solar five-minute oscillations. Analysis yields, among other parameters, the lifetimes of the various modes and the rotation of the Sun deep in its interior. Both observations and theory need and will receive refinement to allow further deductions about solar convection and solar structure. This award is made under the Presidential Young Investigators Program to a young physicist who has already excelled in the field of solar seismology. He explores the solar interior using techniques much like those used in terrestrial seismology to explore the interior of the Earth. He has built and brought into operation two telescopes suited to measure very accurately both the shape and the oscillations of the Sun. He has demonstrated the ability to use the data for significant interpretations. Solar seismology promises fundamental new insights into practical problems such as the understanding of convection and into astrophysical problems such as the emission of neutrinos and the internal rotation of stars. Libbrecht has shown initiative in teaching by building a telescope for the use of undergraduate students.
