In December 2011, a comet passed just above the surface of the Sun, and it survived for a day and a half before disintegrating. It was 37 times larger than the object that exploded in the sky above Siberia this past February.
Comet Lovejoy was a member of a large family of sun-grazing comets that move along the same orbit, all fragments of a much larger body that broke apart centuries ago.
This unique event will be the topic of discussion for the 2013 Bernard Cooper Lecture scheduled for Thursday, April 25. The public lecture will begin at 7 p.m. in Ming Hsieh, room G20, and will feature speaker John Raymond, a physicist from the Harvard-Smithsonian Center for Astrophysics. Alan Bristow, assistant professor of physics, heads the Department of Physics Colloquium Committee and is coordinating this year’s Cooper Lecture.
“For nearly a decade the Cooper Lecture has been the highlight of the Department of Physics’ calendar when the department invites world-renowned scientists to showcase important and exciting developments in physics and/or astronomy,” Bristow said. “This year the department is honored to host Professor John Raymond. He will tell us about the life and death of sun-grazing comets and how they can probe the Sun’s corona.”
Raymond studies spectra of the solar corona, which is the extended outer atmosphere of the Sun where the temperature is millions of degrees. He will describe the way Sun-grazing comets come to an end, and how the death of the Lovejoy comet is being used to better understand the Sun’s corona. This is especially relevant considering the increased awareness of comets and asteroids coming close to Earth and entering our atmosphere.
“Comet Lovejoy gave us the opportunity to watch an object far larger than the one that exploded over Siberia last month as it passed just above the surface of the Sun, only to completely disintegrate a day later,” Raymond said. “We cannot send satellites into the corona of the Sun, but Comet Lovejoy presented a unique opportunity to probe the conditions in the corona all along its path.”
Raymond received his doctorate from the University of Wisconsin, Madison. He specializes in the physics of solar eruption, including observations of shock waves, magnetic reconnection and heating. He also studies the shock waves generated by supernova explosions and the winds from disks surrounding black holes. Raymond has participated in NASA missions that performed ultraviolet observations.
For more information, contact Valerie Burgess, at 304-293-4888 or Valerie.Burgess@mail.wvu.edu