Faculty Profile
Catrina Hamilton-Drager
Associate Professor of Physics and Astronomy (2006)
Contact Information
Tome Scientific Building
717-254-8935
Bio
Professor Hamilton-Drager's research focuses mainly on young stars in the process of forming. She has examined the rotation rates of stars in clusters of different ages to trace the evolution of angular momentum. Stars naturally spin up as they contract while forming (like the ice skater who pulls in her arms). However, some stars are observed to spin fast (P < 2 days), while some spin slowly (3 < P < 14 days). Her research is exploring the interaction of the star's magnetic field and its circumstellar disk, or the material out of which planets will eventually form. Looking at stars in clusters of varying ages (1, 3, 5, 10 million years) allows one to assess exactly how long it takes for stars spin up and thereby infers a possible length of time associated with planet formation. As the disks dissipate, due to planet formation or other factors (high energy winds from nearby hot stars), the stars are freed and allowed to spin up. Professor Hamilton-Drager is probably best known for her pioneering work on the young stellar system known as KH 15D. The KH 15D system is a binary system surrounded by a circumbinary ring. Its light output has been evolving since ~1960 as a result of the gradual precession of the ring in front of the orbit of the binary. The ring acts as a natural coronagraph and provides us with information about the close environment of one of the stars. Her spectral observations show that star A's magnetosphere varies with time, sometimes compact (~1 stellar radius), while at other times, substantially larger (~2 stellar radii or more). There is also evidence for enhanced accretion following periastron passage (generally larger flux values during egress than ingress) as predicted by the models of gas flow from a circumbinary disk through a gap to the binary.
Education
- B.A., Mount Holyoke College, 1991
- M.S., Arizona State University, 1994
- Ph.D., Wesleyan University, 2003
2026-2027 Academic Year
Fall 2026
PHYS 131 Workshop Physics
An introduction to classical mechanics using an inquiry-based, hands-on approach that combines cooperative learning with the use of computer tools for data acquisition, analysis, and mathematical modeling. Both analytic and numerical calculations are introduced for characterizing motion. A selection of kinesthetic experiments is included to enhance student learning. Topics include kinematics, Newton's laws of motion, gravitation, conservation laws, and rotational motion. Recommended for physical science, mathematics, and pre-engineering students and for biology majors preparing for graduate study. Three two-hour sessions per week. Because of the similarity in course content, students will not receive graduation credit for both 131 and 141. Prerequisite: Completion of, or concurrent enrollment in, MATH 151 or 170.
PHYS 141 Physics for the Life Sciences
Introductory, non-calculus physics, principally for life science and pre-med students. Topics include mechanics, fluid dynamics, thermodynamics. Three one-hour lectures and one three-hour lab per week. Because of the similarity in course content, students will not receive graduation credit for both 131 and 141.
Spring 2027
ASTR 109 Mysteries of the Solar System
This course explores questions that are as old as humanity; you will step into the shoes of ancient astronomers to ponder the workings of the night sky and Solar System. Why do the stars move the way they do? Why do some bright objects wander the night sky? Can we know what these objects are and where they came from? We will develop practical and critical thinking skills that are crucial to the art of discovery, focusing on the historical use of naked eye and telescopic observations, as well as the use of present day space probes and the electromagnetic spectrum. Our journey will take us to the planets and some fascinating moons. Three hours classroom, one two-hour laboratory a week. This course counts toward the astronomy minor.
ASTR 306 Observational Techniques
Cross-listed with PHYS 306-01.
This course has been designed to give students an introduction to current observational techniques used to study variable stars. Students will make observations with the °µÍø½ûÇø 24-inch telescope and then analyze those data using multiple techniques. An introduction to AstroImageJ and Python will provide students with the tools needed to complete their analysis. Nighttime sessions, in addition to the weekly class meetings, will be necessary on clear nights to obtain data for the required project. (one credit)
PHYS 306 Observational Techniques
Cross-listed with ASTR 306-01.
This course has been designed to give students an introduction to current observational techniques used to study variable stars. Students will make observations with the °µÍø½ûÇø 24-inch telescope and then analyze those data using multiple techniques. An introduction to AstroImageJ and Python will provide students with the tools needed to complete their analysis. Nighttime sessions, in addition to the weekly class meetings, will be necessary on clear nights to obtain data for the required project. (one credit)