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The PSR J0250 + 5854 was discovered with the aid of an international radio-interferometric facility.
An international team of astronomers from France, the Netherlands, the United Kingdom, South Africa, Australia and Russia has discovered an unusual pulsar whose rotation period is 23 , 5 seconds, making it the slowest known object. In addition, it was previously thought that pulsars with such a long rotational period simply could not exist. Details about the opening described in Preprint, published in the arXiv.org repository.
Until now, the rotation periods of all known pulsars ranged from 1.4 milliseconds (the fastest) to 12.1 seconds (the slowest). One of the tools for finding these objects is a giant Arecibo radio telescope, however, slow pulsar detection is difficult due to the presence of low frequency "red" noise. The algorithms used to "clean" the noise, decrease the sensitivity to dolgoperiodnykh pulsars, and the duration of observation of a single object often does not exceed several minutes. Slowly rotating pulsars often detected the emission of high-energy (X-ray) radiation, for example, Magnetar and XDINS (X-ray isolated neutron stars).
PSR J0250 + 5854 was discovered using international interferometry for the LOFAR (LOw Frequency ARray) installation and observed using other telescopes, including the Green Bank radio telescope and the Observatory radio telescope. ROSAT and Swift. The largest dispersion measurements (DM) that specify the number of refractive radiology of electrons between the observer and the pulsar, the scientists determined that the distance to a neutron star was about 1.6 kiloparsec (more than five thousand light years).
A graph of the pulsar rotation period and the deceleration rate of the pulsar shows that the PSR J0250 + 5854 is the so-called line of death (dead line eng.), When the neutron star is supposed to stop emitting radio waves. One of the hypothetical mechanisms of radio waves is the birth of particles and antiparticles near the poles of the pulsar, in a vacuum zone where the electric and magnetic field is not orthogonal and can maintain a high potential difference. However, for a sufficiently large period of rotation, the potential difference is not sufficient to create pairs and radio waves.
According to another model, a part of the energy released by the deceleration of the pulsar rotation can, with maximum efficiency, "extend" during the establishment of the radio transmission. This creates the "valley of death" in which objects such as PSR J0250 + 5854 can still exist, bypassing the traditional death line. In conclusion of physics, there must be many more pulsars with an extremely long rotation period.
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