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Star eats companion

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16.09.2005

In the scenario proposed by the astrophysicists, the gas from the companion star is channeled along the magnetic field lines until it slams into the pulsar magnetic poles. This gas, heated to extreme temperatures, produces high-energy photons. These photons, emitted periodically at the pulsar rotation frequency, are detected by the INTEGRAL satellite. Additional observations by NASA’s Rossi X-ray Timing Explorer show that during the cannibalization of the companion star, the pulsar spins faster and faster. The star’s matter, attracted by the very strong pulsar gravitational field, supplies the energy needed to accelerate the pulsar rotation.

This binary pulsar, known as IGR J00291+5934, was discovered thanks to the INTEGRAL’s sensitive detectors, during a routine scan of the Milky Way on 2004, December 2. Follow-up observations with the Rossi X-ray Timing Explorer satellite, designed to study rapid time variations, fund the pulsar period to be very fast, with a revolution every 1.67 milliseconds. The low mass companion star was founded to be approximately 40 times the Jupiter mass with an orbital period around 2.5 hours.

This fast-spinning pulsar is the first discovered by INTEGRAL and the fastest of a six members family. These observations back up the hypothesis that fast-spinning isolated pulsars are the consequence of this absorption process.

Célie Simeray | Source: alphagalileo
Further information: www.cea.fr

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