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What is the news?
An international group of astronomers has obtained the first clues about extremely rare giant eruptions lasting 3.5 milliseconds that emerged from a magnetar located 13 million light years away.
What are Magnetars?
When massive stars like supergiant stars with a total mass of between 10 and 25 solar masses collapse, they might form neutron stars. Among neutron stars (neutron stars are the remnants of giant stars that died in a fiery explosion known as a supernova. They have a mass of about 1.4 times that of the sun) stands out a small group with the most intense magnetic field. These are known as magnetars.
Magnetars experience violent eruptions or intense bursts in the form of transient X-ray pulses which are several orders higher than that of the Sun. Even inactive magnetars can be thousands of times more luminous than the Sun.
So far, only 30 magnetars located within the Milky Way have been discovered.
What is the study undertaken by Astronomers?
There was a massive giant eruption that occurred in 2020 from a magnetar named GRB2001415. This eruption released energy equivalent to what the Sun would radiate in one lakh years.
The eruption was detected by the Atmosphere-Space Interactions Monitor (ASIM) on board the International Space Station.
The Astronomers studied why this eruption took place.
What did they find out?
Like earthquakes on Earth, magnetars suffer starquakes produced on their crust due to high instability prevailing in their magnetospheres.
This instability triggers Alfven waves that are also common in the Sun. The interactions between multiple Alfven waves ultimately release massive energies, appearing as giant flares lasting for a few milliseconds.
What is the significance of this study?
Firstly, this is the first extragalactic magnetar studied in detail.
Secondly, understanding these eruptions can shed light on the structure of these mysterious objects.
Thirdly, the study could also further pave the way in linking how magnetic stresses are produced around neutron stars.
Source: This post is based on the article ‘Scientists trace first clue to understand transient high energy pulses from magnetars several thousand times to that of the Sun’ published in PIB on 23rd Dec 2021.