Research Interests

Donald F. Collins, PhD
Department of Physics
Warren Wilson College


These are all projects in which upper division students may pursue for Natural Science Seminar Research.  A student must have taken Physics I (or Astronomy when appropriate) before beginning any of these projects.

Galilean Satellite eclipse timings (in collaboration with Anthony Mallama)

Photovoltaic Solar Collector

Stellar Color Photometry with CCD detectors

Development of unconventional astronomical imaging detectors (digital camera, web camera)

Acoustics studies in archetectural structures (in collaboration with Dr. Alan Coppens)

Development of instrumentation to monitor water quality

Development of educational innovations in physics laboratories

Galilean Satellite eclipse timings (in collaboration with Anthony Mallama)

The four large satellites of Jupiter (Io, Europa, Ganymede, and Calisto - all discovered by Galileo Galilei in the 17th century) enter or exit Jupiter's shadow with almost every orbit.  By photographing these events in rapid sequence with a CCD camera attached to a small telescope, the light curves of the egressing or ingressing satellite can be obtained.  By fitting the light curves with appropriate models of the motion of the satellite, the time resolution of these events can be calculated to with a few seconds - an impossibility as recently as 12 years ago.  The Jupiter system represents a many body problem in celestial mechanics.  The satellites not only are influenced by the tremendous gravity of massive Jupiter and the perturbations of Jupiter's slightly non-spherical shape, but the satellites are also influenced by the mutual gravitional effects of each other.  The inner three satellites are "locked" in periods 1:2:4 respectively.  In addition, the non-circular orbits of the satellites create tidal oscillations that dissipate energy in the satellites further evolving their orbits.  By studying the eclipse timings with a resolution of a few seconds over a period of several years, we have been observing the evolution of the satellite orbits as a result of many celestial mechanics factors.
 
 
Recent publications:
“Precise Timings of Galilean Satellite Eclipses and Assessment of the E5 Ephemeris”, Anthony Mallama, Donald F. Collins, Peter Nelson, James Park, and Bruce A. Krobusek, Icarus 147, pp. 348-352 (2000)

“The Radius of Jupiter and its Polar Haze”, Anthony Mallama, Bruce A. Krobusek, Donald F.  Collins, Peter Nelson and James Park, Icarus 144, pp. 99-103 (2000).

"Precise Timings of Galilean Satellite Eclipses and Assessment of the E-3 Ephemeris", Anthony Mallama and Douglas S. Caprette; Peter Nelson and James Park; Donald F. Collins and Michal Vojtisek-Lom; Icarus 107, pp 212-214 (1994)

Photovoltaic Solar Collector

Warren Wilson College has recently installed a photovoltaic solar collector for the purpose of generating electric power and eliminating some air pollution.  This collector currently provides the electrical energy to charge batteries for electric powered utility vehicles for the physical plant.  A scientific study has recently begun (Chemistry major Sam Frueh) which will accomplish  the following goals and measurements: The system currently is underutilized.  There is much more energy generated than consumed by charging the electric vehicles.  What is the best way to utilize this "surplus" of energy?