For over a decade, astronomers have detected intense bursts of radio energy, or fast radio bursts (FRBs), whose origin and cause are unconfirmed. FRBs are invisible to the human eye, but show up brightly on radio telescopes. Some experts have even said it could be extra-terrestrial radio beams, evidence of alien technology. Now, a new study suggests they are caused by “starquakes” on spinning neutron stars — the collapsed core of a massive supergiant star.
FRBs, first discovered in 2007, can travel billions of light years but usually last just thousandths of a second. It has been estimated that as many as 10,000 FRBs may happen every day if we could observe the entire sky, a Science Daily report explains. In a 2021 study, published in the journal Nature, an international team of astronomers recently observed more than 1,650 fast FRBs detected from one source in deep space, which is the largest set so far.
In the new study, researchers from the University of Tokyo, led by Professor Tomonori Totani, investigated the time and energy of about 7,000 FRBs previously reported to understand their cause. This process revealed striking similarities between FRBs and earthquakes, a report on Earth.com said. However, the analysis showed a distinct difference between FRBs and solar flares, which are massive explosions on the sun when magnetic energy that has built up in the solar atmosphere is suddenly released.
The study reports that evidence points towards the presence of a solid crust on the surface of neutron stars, and that starquakes suddenly occurring on these crusts release massive amounts of energy which we see as FRBs.
“The interior of a neutron star is the densest place in the universe, comparable to that of the interior of an atomic nucleus. Starquakes in neutron stars have opened up the possibility of gaining new insights into very high-density matter and the fundamental laws of nuclear physics,” Totani says in a press statement by the University of Tokyo.
Moreover, by studying starquakes on distant ultradense stars, which have different environments from Earth, scientists may gain new insights into earthquakes, the researchers added in the statement.