An international team of astronomers has discovered a second fast radio burst that keeps repeating. This raised the question of what underlies this mysterious phenomenon, according to Space.. com.

Fast radio bursts (FRBs) are intense, short bursts of radio frequency radiation that last milliseconds.. The phenomenon was discovered in 2007, but the source of these extremely energetic events is still a mystery to researchers..

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A new burst, FRB 20190520B, has been detected by the FAST telescope in China. It was recorded on May 20, 2019 and found in the data in November of the same year..

Further observations using the Jansky Very Large Array (VLA) program found faint, constantly repeating emissions associated with this radio burst.. This allowed the Subaru telescope to localize its source within a dwarf galaxy located at a distance of three billion light years from Earth..

This is the second discovery of a repeating fast FRB, the first was made in 2012. According to scientists, the second signal became the "

The discovery raises new questions about the nature of these signals.. For example, can the source of the FRB change over time, and are the sources different for different FRBs?.

“One of the key questions in the field of FRB is whether all FRB sources are repeated. Personally, I prefer an evolutionary picture in which all sources are repeated, but the level of activity drops sharply as the source ages.. This is only the second of 500 known FRBs to recur and have a " In this hypothetical evolutionary picture, they may represent the youthfulness of the FRB, which does not last long,” said Di Li of the National Astronomical Observatory of China (NAOC).

Another feature of FRB 190520B is its dispersion indexes, which indicate that its emissions passed through the highest electron density of any FRB before being detected on Earth.. This suggests that the FRB is active in a local plasma environment, such as that created by a supernova, and is a recently emerging source.

Earlier, scientists from the National Astronomical Observatory of the Chinese Academy of Sciences using the world's largest radio telescope FAST discovered three fast radio bursts. These radio bursts happened billions of years ago, when the universe was young, the researchers say..