Image: The unusual PSR J1311-3430 pulsar system (magenta) is so compact that it would fit completely inside our sun. This schematic representation shows the sun, the companion’s orbit, and the companion at its maximum possible size true to scale; the pulsar has been greatly enlarged in contrast.
Astronomers have discovered an ultra-dense star that orbits with a dying stellar companion once every 93 minutes, making it the fastest-orbiting star of its kind.
The speedy object, a kind of neutron star called a millisecond pulsar, rockets through space at 8,100 mph (13,000 kph) or more, researchers said. Its lightweight companion — which the “black widow” pulsar is destroying with a barrage of radiation — is faster still, zipping around the system’s common center of mass at 1.7 million mph (2.8 million kph) or so.
The pulsar, known as PSR J1311-3430, and its partner are separated by just 320,000 miles (520,000 kilometers) — about 1.4 times the distance from Earth to the moon — making them the most tightly bound such pair known.
Scientists spotted PSR J1311-3430 after combing through four years’ worth of data collected by NASA’s Fermi Gamma-Ray Space Telescope. The find marks the first time a millisecond pulsar (MSP) has been detected via high-energy gamma rays alone, researchers said.
“The discovery of this first MSP from direct gamma-ray pulsations opens the door to the detection of other extreme binary pulsars,” study lead author Holger Pletsch, of the Max Planck Institute for Gravitational Physics (Albert Einstein Institute) in Hanover, Germany, told SPACE.com via email. [Top 10 Strangest Things in Space]