In the vast catalog of violent cosmic events, there are explosions and then there are superluminous supernovae, which are nothing more than the result of a stellar death which is capable of shining up to 100 times brighter than a conventional supernova, challenging our understanding of astrophysics for years, since it is not known where it can get so much energy from. Now we are getting an idea.
What do we know? The big news in the world of astrophysics comes from an international team of astronomers who has been able to observe for the first time the live birth of a magnetar, conclusively confirming the link between these highly magnetic stellar corpses and the brightest supernovae in the cosmos.
Where. The protagonist of this discovery is SN 2024fav, a type I superluminous supernova detected on December 9, 2024 and located in the Eridanus constellation about 1,000 million light years from us. And it’s not that it is a very common phenomenon, because watching this event is like looking for a needle in an intergalactic haystack.
Finding this ‘needle’ is something very precious and that is why, in order not to lose any detail of this brilliant monster, the astronomical community mobilized a network of more than 20 telescopes around the world, including the fundamental contribution of the LOCGT. Thanks to this uninterrupted surveillance, scientists obtained the observational data necessary to reconstruct what was happening in the depths of the explosion.
The relativistic screech. The question here is pretty clear: how do you confirm that there is a magnetar inside that expanding fireball? The first thing is to know what a magnetar is, which is nothing other than a very dense neutron star that has a magnetic field trillions of times stronger than that of the Earth. And it is not static, because when born after the collapse of a massive star it can rotate several times per second, reaching high speeds.
In order to discover it, the researchers have named what gave them the key ‘relativistic chirp’. In this way, as the newborn magnetar rotates at the center of the supernova, its immense magnetic field acts as a brake, transferring its colossal rotational energy to the ejected stellar matter, causing it to shine with such extreme intensity.
What they saw. From here, the researchers precisely detected the temporal signature of this external braking. From here, the light curve of SN 2024afav fit perfectly with the prediction of the energy loss of an incipient magnetar injecting power into the supernova, so we are facing the birth of a magnetar.
Its importance. This discovery not only allows us to understand why certain stars say goodbye to the universe with a blinding brightness capable of eclipsing entire galaxies, but also opens a new window to study the behavior of matter subjected to such extreme magnetic fields that modern physics can barely replicate on paper.
Images | NASA Hubble Space Telescope
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