NEWS INDEX Archives 2004 November

Distinguished German astrophysicist to present public talk

James E. Kloeppel, Physical Sciences Editor
217-244-1073; kloeppel@uiuc.edu

11/2/04

CHAMPAIGN, Ill. — Reinhard Genzel, director of the Max Planck Institute for Extraterrestrial Physics in Garching, Germany, will discuss black holes during a talk Nov. 17 at the University of Illinois at Urbana-Champaign.

Genzel, who also is a professor of physics at the University of California at Berkeley, will present the seventh talk in the U. of I. department of astronomy’s Icko Iben Jr. Distinguished Lectureship. The lecture, “Massive Black Holes, or Gravity Strikes Back,” begins at 7 p.m. in Foellinger Auditorium, 709 S. Mathews Ave., Urbana. The talk is free and open to the public.

“Reinhard Genzel is the leading authority on the observational evidence for the existence of black holes,” said Lewis Snyder, the chair of the astronomy department. “His talk, which will present strong evidence for a massive black hole lurking at the center of our Milky Way galaxy, should be of interest to faculty, students and the general public.”

A black hole is a region of space-time with an intense gravitational field from which matter and energy cannot escape. “Supermassive black holes represent the edge of known physics,” Snyder said, “and offer an extreme case for testing and clarifying many aspects of Albert Einstein’s theory of general relativity.”

Two years ago, Genzel, together with more than 20 astronomers and physicists, announced the discovery of a monstrous black hole, more than 3 million times as massive as the sun, at the center of the Milky Way. Genzel’s team had tracked the path of a star hurtling around the black hole at more than 3,000 miles a second. The star’s orbit, roughly the diameter of our solar system, could ultimately end in the star’s violent death within the black hole. Each orbit takes about 15 years to complete.

The black hole at the galaxy’s center is known as Sagittarius A, because it appears to lie in the southern constellation Sagittarius (“The Archer”).

Black holes are a leading research problem in cosmology, Snyder said. “A better understanding of these mysterious objects could lead to new physics, which might help scientists identify the missing dark matter and dark energy in the universe.”

Genzel was appointed director of the Max Planck Institute for Extraterrestrial Physics in 1986. He spends a quarter of each year as a physics professor at Berkeley.

Each year the Iben lectureship brings a noted astronomer to campus to highlight some of the latest developments in astronomy, Snyder said. In addition to giving a public lecture, the invited speaker also will give a technical colloquium and meet informally with faculty members and students.