Magnetar: a cataclysmic explosion 13 million light-years away
Credits: NASA Goddard Space Flight Center/Chris Smith (USRA))
Millions of years ago, a magnetar spun off its hinges, releasing as much energy as a billion suns in a fraction of a second. Two years ago, an instrument available on board the ISS was able to capture this incredible event. Astronomers think these high-energy explosions are caused by "starquakes."
Neutron stars and magnetars
A neutron star forms when the core of a massive star collapses at the end of its life under the effect of gravity. As the star dies in a supernova, it ultimately leaves behind only a small object composed almost entirely of neutrons held together. Physically, a neutron star is about 1.3 to 2.5 solar masses (about 330,000 Earths) packed into a sphere only twenty kilometers in diameter.
Magnetars are neutron stars whose magnetic fields are at least a thousand times stronger than those of other neutron stars.
We know that these objects, which can be thousands of times brighter than our Sun, can “flare up” spectacularly. Unfortunately for researchers, these eruptions are often very sudden and incredibly brief, and therefore difficult to study . However, difficult does not mean impossible. A team of astrophysicists has indeed recorded one of these events.
Artist's impression of a magnetar. Credits: ESO / L.Calçada.
A cataclysmic eruption
The magnetar in question is located in the Sculptor's Galaxy, a spiral galaxy found about thirteen million light-years from Earth. The eruption was detected on April 15, 2020 by the Atmosphere-Space Interactions Monitor (ASIM) instrument, available on the International Space Station.
According to the analyses, this distant object would have released as much energy as our Sun produces in 100,000 years, and this, in only 0.16 seconds , before “extinguishing” as suddenly.
" It is as if this magnetar had decided to reveal his existence 'from his cosmic solitude' by shouting into the void of space with the force of a billion suns ", points out Alberto J. Castro-Tirado, of the Institute of Astrophysics of Andalusia of the Spanish Council.
In the journal Nature, the authors point out that they spent more than a year analyzing ASIM data, dividing the event into four phases based on the magnetar's energy output and variations in its magnetic field.
This study is important because only about 30 magnetars have been identified out of about 3,000 known neutron stars. Furthermore, it is the most distant eruption detected so far for such an object. Astrophysicists suspect that these events could be caused by alleged "starquakes" capable of disrupting the highly "elastic" outer layers of magnetars.
Source: websites