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| An illustration showcases IGR J17062–6143, a binary star system featuring a pulsar and its companion, from which the neutron star is steadily stealing stellar material. Photo by NASA's Godard Space Flight Center |
By Brooks Hays, UPI
Scientists have found a pair of stars orbiting one another at record speed.
The duo orbit each other once every 38 minutes, the shortest-known orbital period for its specific class of pulsar binary systems.
The unusual pair, named J17062, was discovered while interrogating the first batch of data recorded by the Neutron star Interior Composition Explorer mission, or NICER mission.
According to researchers, the system is made up of a rapidly spinning, superdense neutron star called an accreting millisecond X-ray pulsar and a hydrogen-poor white dwarf.
"It's not possible for a hydrogen-rich star, like our sun, to be the pulsar's companion," Tod Strohmayer, an astrophysicist at NASA's Goddard Space Flight Center, said in a news release. "You can't fit a star like that into an orbit so small."
Neutron stars are the extremely hot, superdense stellar cores sometimes left over after supernovae. The stars are so hot, they emanate X-rays. Their violent spin and its accretion from its companion causes intense beams of X-rays to pulse from their poles.
NICER data showed J17062 pulses 163 times per second, which means the pulsar is spinning at a speed of 9,800 revolutions per minute. Though J17062 boasts a record orbit, its spin rate is average. Some pulsar spin some 700 revolutions per second, several orders of magnitude greater than J17062 spin rate.
The hotspots that produce the neutron star's polar pulses are created by the accretion of material from its companion, the hydrogen-poor white dwarf. Stolen material is pulled into an accretion disk, much like a black hole. Because the pulsar has an intense magnetic field, the material in the accretion disk are pulled into the stellar core unevenly, creating hotspots.
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