International teams of astronomers say they've analyzed gamma-rays from two dozen pulsars, including 16 discovered by Fermi.
A pulsar is the rapidly spinning and highly magnetized core left after a massive star explodes, NASA said.
"Since the demise of the Compton Gamma Ray Observatory a decade ago, we've wondered about the nature of unidentified gamma-ray sources it detected in our galaxy," said Paul Ray of the Naval Research Laboratory in Washington. "These studies from Fermi lift the veil on many of them."
The new pulsars were discovered as part of a comprehensive search for periodic gamma-ray fluctuations using five months of Fermi Large Area Telescope data and new computational techniques.
Fermi was launched in June 2008 as a joint venture of NASA, the U.S. Department of Energy and partners in France, Germany, Italy, Japan and Sweden.
"Before launch, some predicted Fermi might uncover a handful of new pulsars during its mission," said Marcus Ziegler, a scientist at the University of California-Santa Cruz. "To discover 16 in its first five months of operation is really beyond our wildest dreams."
The two studies appear in the online journal Science Express in advance of print in Science magazine.