BRENT: Pulsars are rapidly rotating compact remnants born in the explosions of massive stars. They can be observed through their lighthouse-like beams of radio waves and gamma-rays. Scientists at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI) in Hannover, Germany, now have precisely measured the properties of a binary star system with a gamma-ray millisecond pulsar. Using new methods, the researchers analyzed archival data from the Fermi Gamma-ray Space Telescope more precisely than possible before. They discovered variations in the orbital period of the interacting binary system that can be explained by magnetic activity cycles of the companion star.
0FGL J2339.8–0530 – that is the catalog name of a celestial object which the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope identified as a source of intense gamma radiation in 2009. Observations at other wavelengths in the following years suggested a possible explanation for its nature: a millisecond pulsar in a binary system with a companion star, each orbiting their common center of mass every 4.6 hours.
Only in 2014 could the pulsar now known as “PSR J2339–0533” be identified through its pulsed radio emission. The observations at radio wavelengths are hampered through the interaction of the pulsar with its stellar partner. The pulsar’s radiation heats the companion and slowly vaporizes it. This causes clouds of gas to drift through the binary system, which absorb the radio emission and temporarily make the pulsar invisible. To completely characterize the system, regular observations over several years would be required.
