U. prof finds key to learning how planets are born

For recently hired Astrophysics Professor David Koerner, spending some time in Hawaii last March was not all fun and sun. Koerner, then a NASA Jet Propulsion Laboratory researcher, was busy doing work of a more serious nature: discovering a new solar system. Perched atop a dormant volcano in Hawaii at the site of Keck II, the world's largest telescope, Koerner and his team of three astronomers were looking for signs of planetary systems forming around stars. And they found what they were looking for: Using Keck II in conjunction with a mid-infrared camera to look at infrared heat radiation emitted from a star 1,320 trillion miles from Earth, Koerner and his team located HR4796 -- a disk of dust with a hole in it, rotating around a star in the Centaurus constellation. To Koerner and the rest of the scientific community, the discovery represents the key to understanding the formation of solar systems like ours. "The interesting thing about this disk is that it has a big hole in it the size of a solar system," Koerner said. "We think that based on this and other examples, that planetary formation occurs when a hole opens up in the disk and planets are formed." According to Koerner, planets are formed when material left over from a star formation is spun into a disk and left in orbit. After a few million years, these pebble-size bits of material accumulate into planets. Although they were the first humans to actually set eyes on the disk, Koerner and his team were not the first or only group to record and observe the image in a four-day time period. Just a few hours prior to Koerner's viewing on the disc, on the night of March 15, photographs of the star and ring of surrounding dirt were taken by the Hubble Space Telescope, but were not observed by the Hubble team. And two days after Koerner's discovery, a team of scientists from the Harvard-Smithsonian Center for Astrophysics observed the image from a telescope in Chile. Members from both the Chilean team and Hubble were unavailable for comment. Koerner's involvement in the discovery of the disk is not only bolstering his own reputation -- he has received press coverage from major news media including The New York Times, Time, Newsweek and The Washington Post -- but is also improving Penn's reputation in the area of astrophysics. "Whenever you have one of the people featured in a Newsweek cover story it's going to have a very good effect on Penn's reputation," Physics and Astronomy Department Chairperson Paul Langacker said. After earning his doctorate in planetary science from the California Institute of Technology and working in NASA's Jet Propulsion Laboratory, Koerner was the department's No. 1 recruit last year. And despite making such a monumental discovery, Koerner has not allowed his prominence to interfere with his teaching. Since his arrival at Penn last July, Koerner has been praised for the enthusiasm and knowledge he brings to the classroom. "It's not only his reputation but what he's doing in class that's great," Langacker said. "He is working with 18 undergraduate research students and exposing them to his type of work." Koerner's recruitment last July was part of a College of Arts and Sciences initiative to strengthen the Astrophysics Department. "Astrophysics is a hot topic of research interest which has captured the imagination," said School of Arts and Sciences Associate Dean David Balamuth, a Physics professor. "Astronomy and astrophysics are of great interest to undergraduates." Koerner will be speaking at the summer meeting of the International Society for the Study of the Origin of Life in San Diego and will be talking in South Korea this summer about astrophysics. Koerner is also working on a book entitled Cosmic Life: The Scientific Quest for Our Place in the Living Universe.