NASA's Fermi Gama-ray Space Telescope recently identified an "exceptional" binary system that not only contains a rapidly spinning neutron star called a pulsar, but also a relatively small yellow star. Interestingly, close examination revealed that this second star serves much like a dance partner for the pulsar, causing it to exhibit some unusual behavior.

According to NASA, Fermi readings first identified unusual behavior from the pulsar J1023 at the start of 2013.

Because of their incredibly fast spinning, pulsars tend to emit two streams of radio waves from either pole, creating a beacon that looks similar to an hour glass. However, this beacon suddenly vanished in late June, giving way to a five-fold increase in gamma ray readings.

"It's almost as if someone flipped a switch, morphing the system from a lower-energy state to a higher-energy one," Benjamin Stappers, an astrophysicist at the University of Manchester, England, said in a statement.

Stappers led an international effort to understand this striking transformation. The results were published in The Astrophysical Journal on July 20.

"The change appears to reflect an erratic interaction between the pulsar and its companion, one that allows us an opportunity to explore a rare transitional phase in the life of this binary," Stappers explained.

Anne Archibald of the Netherlands Institute for Radio Astronomy discovered J1023 in 2007. She suggests that the pulsar was formed after a young neutron star was influenced by the nearby standard star (about a fifth of the size of the Sun). Interaction not yet understood likely got J1023 spinning up to 43,000 rotations-per-minute, classifying it as a "millisecond pulsar."

"Astronomers have long suspected millisecond pulsars were spun up through the transfer and accumulation of matter from their companion stars, so we often refer to them as recycled pulsars," she said.

Stappers now suspects that this transfer of matter is what is temporarily containing the radio signals that normally hide the system's gamma rays, with a back-and-forth dance between the two stars keeping the pulsar spinning so rapidly.

A team at NASA's Goddard Space Flight Center recently created a simulation of how it is suspected this dance occurs, and can be viewed below.