In January, astronomers from the Canadian CHIME telescope discovered a beam of energy bursts that proved to be a repetitive source: the Fast Radio Burst (FRB) 180916.J10158 + 56 is picked up on Earth every 16.35 days. But the second FRB to present periodicity is also the most important in the study of this galactic phenomenon that intrigues researchers: the FRB 121102 emits bursts of radio for 90 days, then silence for 67 days. This cycle is repeated every 157 days.
“The huge difference between the two FRBs means that there is a wide range of periodicity in the repetition of the behavior of these energy beams. This regularity astronomically restricts the sources of these explosions; for example, it would be difficult to reconcile it with a neutron star,” he explained. the Manchester University astrophysicist and leader of the study now published in the Royal Astronomical Society’s Monthly Notices, Kaustubh Rajwade, other sources would be a massive star or even a black hole.
The article is the result of four years of long-term monitoring of the Lovell Telescope, operating at the British Jodrell Bank Center for Astrophysics. 32 bursts were discovered and, joining the information collected with the data from previous observations, the cyclical emission pattern of FRB 121102 was reached.
The most intriguing is the most studied
When FRB 121102, located 3 billion light years ago, launched its energy beams that are now being captured, Earth was a lifeless planet, probably without continents and covered in water. Since it was discovered in 2012, no other FRB has been studied more.
The first FRB was discovered in 2007 through the analysis of data captured in 2001 by the CSIRO Parkes Radio Telescope, in Australia: hidden between years of collected information, was a 5 millisecond explosion, whose source appeared to be the Little Magellanic Cloud, nearly 200,000 light years ago. It was called FRB 010724 (or Lorimer Burst, after the astrophysicist Duncan Lorimer, who discovered it).
Currently, there are more than a hundred of these extragalactic flashes of light, which release in milliseconds the same energy that the sun emits in a century of activity. Most shines only once and does not repeat itself.
Search for signs of extraterrestrial intelligence
One of the auxiliary projects in the search for FRBs is the Breakthrough Listen which, since January 2016, looks for signs of extraterrestrial intelligence (the search ends in 2026). Its base is the SETI Research Center of the Department of Astronomy at the University of California, Berkeley, USA.
The program examines radio wave observations from the CSIRO Parkes Radio Telescope and Green Bank Observatory, as well as data obtained via visible light observations from the Automated Planet Finder (an automated telescope from the Lick Observatory).
About a million nearby stars and the centers of a hundred galaxies are monitored. The program also reviews, via search algorithms, data compiled from decades of astronomical observations around the world - mainly FRB records.
“More data on more FRBs will be needed to have a clear picture of these periodic sources of energy and to elucidate their origin,” says Lorimer, who is now associate dean of research at West Virginia University and, along with physicist Devansh Agarwal, developed the data analysis technique that led to the discovery of the frequency of FRB 121102.
