An orbiting star begins to eclipse its partner, a rapidly rotating, superdense stellar remnant called a pulsar. Image courtesy of Aurore Simonnet/Sonoma State University/NASA
Jan. 26 (UPI) -- NASA made a first-of-its-kind discovery with its Fermi Gamma-ray Space Telescope, spotting the first gamma-ray eclipses from a special type of star system.
The agency shared the news with Nature Astronomy on Thursday after scientists researched a decade of observations from the telescope that can detect the most astonishing celestial events from gamma bursts to black holes.
Gamma-ray eclipses were observed from a special binary star system that is orbited by what is called a spider system. Binary systems are two stars that have a gravitational pull toward and rotate around each other.
A spider system includes the remnants of a star that exploded in a supernova, called a pulsar. This cosmic phenomenon has piqued the curiosity of astronomers due to their rhythmic flicker.
"One of the most important goals for studying spiders is to try to measure the masses of the pulsars," said Colin Clark, an astrophysicist at the Max Planck Institute for Gravitational Physics in Hannover, Germany, who led the research team.
"Pulsars are basically balls of the densest matter we can measure. The maximum mass they can reach constrains the physics within these extreme environments, which can't be replicated on Earth."
Since Fermi launched in 2008, it has discovered more than 300 gamma-ray pulsars. One of the pulsars it detected was the first to ever be detected outside of the Milky Way galaxy. It has detected cosmic events such as the merging of neutron stars, and given researchers the ability to map out the the history of such events.
"Before Fermi, we only knew of a handful of pulsars that emitted gamma rays," said Elizabeth Hays, the Fermi project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md.
"After over a decade of observations, the mission has identified over 300 and collected a long, nearly uninterrupted dataset that allows the community to do trailblazing science."