RESEARCH - A cosmic lighthouse visible to the human eye

A team of Italian astronomers led by Filippo Ambrosino (Sapienza University of Rome and INAF-IAPS) and Alessandro Papitto (INAF-OAR) observes for the first time a millisecond pulsar (PSR J1023 + 0038) that emits periodic impulses of visible light.

The results, published in the journal Nature Astronomy, were obtained through the use of the SiFAP (Silicon Fast Astronomical Photometer) optical photometer, designed and realized by Franco Meddi at the Department of Physics of Sapienza, in collaboration with Filippo Ambrosino and with the contribution of astrophysics Roberto Nesci and Corinne Rossi. The photometer was then mounted to the National Galileo Telescope (INAF) to the Canary Islands.

The radio pulsars are neutron stars that behave like real cosmic lighthouses. When the star rotates fast enough, their intense magnetic fields can accelerate particles with very high energies. At each rotation of the star, the accelerated electrons produce observable radiation impulses, ranging from radio waves to gamma rays. An object on their surface then travels at an incredible speed, equal to about 10% of the speed of light.

"Never before had this behaviour been recorded in a celestial object of this category: the pulsar emits 590 light pulses visible every second - Meddi explains - this discovery is important not only because it proves that the magnetic fields of stars of Neutrons in rapid rotation can generate visible light pulsations even in the presence of an accretion disc, but also because it opens up a completely new astrophysics field of investigation”.

Un team di astronomi italiani guidato da Filippo Ambrosino (Sapienza Università di Roma e INAF-IAPS) ed Alessandro Papitto (INAF-OAR) osserva per la prima volta una millisecond pulsar (PSR J1023+0038) che emette impulsi periodici di luce visibile.

Optical pulsations from a transitional millisecond pulsar - F. Ambrosino, A. Papitto, L. Stella, F. Meddi, P. Cretaro, L. Burderi, T. Di Salvo, G. L. Israel, A. Ghedina, L. Di Fabrizio & L. Riverol. Nature Astronomy (2017) doi:10.1038/s41550-017-0266-2

Tuesday, 03 October 2017

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