The millisecond pulsar PSR J1023+0038 is known to switch between two brightness modes almost constantly, something that until now has been an enigma.
PSR J1023+0038 is a 1.69 ms radio pulsar located about 4,500 light-years away in the constellation of Sextans.
Discovered in 2007, it orbits a low-mass (0.2 solar masses) companion star with a period of only 4.75 hours.
Over the past decade, PSR J1023+0038 has been actively pulling matter off this companion, which accumulates in an accretion disk around the pulsar and slowly falls towards it.
Since this process of accumulating matter began, the sweeping beam virtually vanished and the pulsar started incessantly switching between two modes.
In the ‘high’ mode, the pulsar gives off bright X-rays, ultraviolet and visible light, while in the ‘low’ mode it’s dimmer at these frequencies and emits more radio waves.
The pulsar can stay in each mode for several seconds or minutes, and then switch to the other mode in just a few seconds. This switching has thus far puzzled astronomers.
“We have witnessed extraordinary cosmic events where enormous amounts of matter, similar to cosmic cannonballs, are launched into space within a very brief time span of tens of seconds from a small, dense celestial object rotating at incredibly high speeds,” said Dr. Maria Cristina Baglio, an astronomer at New York University Abu Dhabi and the Italian National Institute for Astrophysics.
Dr. Baglio and her colleagues carried out the most extensive multi-wavelength campaign ever conducted on the transitional pulsar, covering from the radio to X-rays.
The campaign involved 12 different telescopes and instruments, including ESA’s XMM-Newton observatory, the NASA/ESA Hubble Space Telescope, the FORS2 instrument on ESO’s Very Large Telescope, the Atacama Large Millimeter/submillimeter Array, NSF’s Karl G. Jansky Very Large Array, and FAST.
Over two nights in June 2021, the astronomers observed over 280 switches between its…
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