UNIVERSITY PARK, Pa. -- X-rays streaming toward Earth from the region near a neutron star that is cannibalizing its companion star have revealed the pair to be the youngest X-ray binary yet known. The discovery by a team that includes a Penn State astronomer is being published in this week's issue of the The Astrophysical Journal.
The team discovered the age of this record-breaking pair, named Circinus X-1, by using data from NASA's Chandra X-ray Observatory, which revealed faint remnants of the supernova explosion that created the neutron star.
"I have been perplexed by the unusually strong evolution of the orbit of Circinus X-1 since my graduate-school days," said Niel Brandt, distinguished professor of astronomy and astrophysics. "The discovery now of this system's youth provides a satisfying explanation for why its orbit evolves so strongly -- because the system likely still is settling down after its violent birth."
The research team, which was led by Sebastian Heinz at the University of Wisconsin-Madison, determined that Circinus X-1 is less than 4,600 years old. "X-ray binaries provide us with opportunities to study matter under extreme conditions that would be impossible to recreate in a laboratory," Heinz said. "For the first time, we can study a newly minted neutron star in an X-ray binary system."