Edith J. Woodward Award of the American Astronomical Society, 1993.

Ph.D., University of Texas at Austin, 1978.

Visiting Assistant Professor, Texas A&M University, 1978-80

Assistant Professor to Professor, University of Arkansas, 1980-1999.

Professor Lacy's primary research interest is in studies of eclipsing binary stars. He has made numerous observing runs at McDonald Observatory, Kitt-Peak National Observatory, and Cerro Tololo Interamerican Observatory (Chile). He is also interested in extrasolar planets and near-Earth objects.

BINARY STARS AND NEAR-EARTH ASTEROIDS

Some of my current research centers on the theory of stellar evolution, especially on methods of testing the validity of its details. I am working as part of an international collaboration to determine accurate fundamental astrophysical data about stars in eclipsing binary and multiple star systems. The types of data we are able to provide include orbital parameters, masses, radii, luminosities, and internal structure of the stars. In order to obtain these data, we need to measure both the brightness as a function of time (the light curve) of the eclipsing binary and the radial velocities of both stars as a function of time (the RV curve). It is possible to measure light curves of these eclipsing binaries with a relatively small telescope. For this purpose we are now using robotic WebScopes in Fayetteville, AR (ursa.uark.edu) and Silver City, NM (www.nfo.edu). Radial velocities are derived from spectra which must be obtained with larger telescopes. Telescopes at McDonald Observatory in Texas and at Kitt Peak National Observatory in Arizona have been used in an ongoing program to obtain digital spectra of our program stars. We now collaborate with astronomers at the Harvard-Smithsonian Center for Astrophysics at Harvard University to obtain very accurate radial velocities. The radial velocities are extracted from spectrograms with computers on campus. Numerical models can be fitted to the photometric and spectroscopic data to derive fundamental astrophysical parameters such as the masses and radii of the stars. We can often measure these data to an accuracy of 1% or better. At this level of accuracy the observations can serve as a critical test of theories of stellar evolution. Theories which cannot match the observations must be rejected. Our efforts are directed to the task of testing our current theories at the highest levels of accuracy attainable.

I am also studying near-Earth objects (NEOs) in support of the proposal by our Arkansas Center for Space and Planetary Sciences (spacecenter.uark.edu) to send a spacecraft to a near-Earth asteroid and bring back to Earth samples of its surface, known as the Hera mission. In order to select the optimum target asteroid, we need to know what type of surface composition it has. We are determining this information by using the 3 m NASA Infrared Telescope Facility on Mauna Kea, HI to get infrared spectrograms of potential target objects. We actually remotely control the telescope and its instruments with a computer in our office on campus in Fayetteville. The spectrograms are analyzed on campus to determine the mineralogy and history of the asteroids' surfaces.