First light. Chandra's image of Cassiopeia A, with a possible neutron star at the center.

First Chandra Images Elate Astronomers

Only 5 weeks have passed since Chandra, NASA's new x-ray observatory, was launched, and already it may have found the youngest known neutron star--the corpse of a dead star--in the Milky Way. A spectacular x-ray image of Cassiopeia A, the remnant of a supernova explosion that happened 320 years ago, shows a point-shaped source of light at its center that "may well be the remnant of the exploded star," says Harvey Tananbaum, director of the Chandra X-ray Center in Cambridge, Massachusetts. "If so, this is really a fabulous discovery," says supernova expert Robert Kirshner of Harvard University The first images obtained by the $1.5 billion telescope, named after the late astronomer and Nobel laureate Subrahmanyan Chandrasekhar, were revealed today at a press conference at NASA's headquarters in Washington, D.C. Apart from Cassiopeia A, Chandra also snapped a distant quasar, revealing a vast tongue of x-ray-emitting particles. "The bottom line is: It works. It works perfectly," says Ed Weiler, NASA's associate administrator of space science.

Chandra is part of NASA's Great Observatories program, which also includes the Hubble Space Telescope and the Compton Gamma Ray Observatory. After several weeks of testing and instrument calibrating, Chandra made its first images last week. The image of Cassiopeia A contains clues to the temperature and composition of the hot debris from the explosion; thanks to Chandra's large, high-quality x-ray mirrors, it shows much more detail than earlier x-ray photos of the supernova remnant, made by satellites like the U.S.-German ROSAT.

Chandra project scientist Martin Weisskopf of NASA's Marshall Space Flight Center in Huntsville, Alabama, who worked on the project for 23 years, says the x-ray observatory is performing according to its specifications. "This is not only a great day for the Chandra team," says Kirshner, "but for all of astronomy. Chandra has a tremendous amount of promise."