Stephen S. Lawrence
Associate Professor of Physics and Astronomy
Degrees: PHD, 1994, Univ Michigan Ann Arbor; MS, 1990, Univ Michigan Ann Arbor; BA, 1988, Univ Chicago
Dr. Lawrence earned a B.A. in physics from the University of Chicago and a M.S. and a Ph.D. in Astronomy from the University of Michigan. His Ph.D. dissertation, "Fabry-Perot Imaging Spectroscopy of the Crab Nebula, Cassiopeia A, and Nova GK Persei" was awarded the University of Michigan Ralph Baldwin Thesis Prize in Astronomy & Astrophysics for 1994. He has held research positions at Columbia University and the National Astronomical Observatory of Mexico and teaching postions at Bowling Green State University in Ohio. He has been a professor at Hofstra University since 2001.
Dr. Lawrence's research interests fall into three main categories: i) supernova explosions and remnants, ii) light echoes and iii) extrasolar planets and astrobiology.
His primary interests involve supernovae (explosions that mark the deaths of stars) and supernova remnants (the rapidly expanding bubbles of hot gaseous debris that they leave behind). Dr. Lawrence's thesis research used Fabry-Perot imaging spectroscopy to create 3-D models of gaseous remnants of the Crab Nebula and Cassiopeia A supernovae as well as the remnant of Nova GK Persei. He is currently working with an international team to monitor the ongoing collision of the debris ejected from Supernova 1987A with rings of circumstellar gas shed by the progenitor star thousands of years before it exploded. As the closest supernova explosion in over 400 years, Supernova 1987A is allowing us to watch the transformation from supernova explosion to supernova remnant in unprecedented detail, using ground-based telescopes in Chile and the Hubble Space Telescope in orbit.
Dr. Lawrence is also collaborating with Prof. Arlin Crotts of Columbia University on the light echo from Supernova 1987A. Much as the flash of light from a shell in a fireworks display will light up the smoke from previous fireworks, the intense burst of light from this supernova 1987A is progressively illuminating clouds of interstellar dust in the nearby galaxy (the Large Magellanic Cloud, or LMC) that contained the supernova. They are monitoring these light echoes in order to map the three-dimensional distribution of dust structures in the LMC, and also to determine the physical properties of LMC dust grains. The echoes appear to move outwards from the supernova at faster than the speed of light, allowing them to sample very large volumes of space in relatively short periods of time.
Dr. Lawrence has also recently developed an interest in the topics of astrobiology (the search for extraterrestrial life) and the detection of exoplanets (planets in orbit of stars other than our own Sun). He is interested in the true range of orbits that populate a habitable zone around a star of a particular mass, given recent advances in our understanding of stellar evolution, orbital evolution of giant planets, tidal heating, and the discovery of subsurface terrestrial life forms that are completely independent of sunlight for survival. Dr. Lawrence is also studying ways in which to detect giant planets in orbit around variable stars and in binary star systems.