Welcome to this week’s AITN Lite! I know it’s a while since the last AITN bulletin, but that discussed the largest cosmic explosion. Here today we are going to discuss the brightest cosmic explosion, GRB221009A. The previously discussed accretion event has given off more energy, but this gamma-ray burst (GRB) has the brightest peak ever seen! The article can be found here:
GRBs are some of the most energetic events in the Universe, and there are two broad categories separated by the time that the burst exists for. Short GRBs are explosions that last for less than 2 seconds, with long GRBs lasting longer than that. Short GRBs are thought to occur from the merger of two small, dense objects such as neutron stars and black holes. However, longer GRBs, such as GRB221009A are unambiguously associated with the end of a high-mass star’s life since they are associated with regions of star formation. High-mass stars don’t live for very long, thus star-formation regions are usually still present when they die.
GRB221009A was first detected by the Fermi and Swift space-based gamma-ray telescopes. However, the flux was so bright that it saturated the detector! The follow-up of GRB221009A across multiple wavelengths, from the x-ray to the radio, along with looking at the emission spectra of previous gamma-ray bursts allowed them to determine it was the brightest ever observed! Since it was a long-duration gamma-ray burst, it is expected that this was the result of a massive star exploding and going supernova. However, the follow-up observations have yet to find evidence of the afterglow of a supernova. It is, therefore, possible that the star collapsed directly to a black hole, such as that discussed in AITN #27. Further follow-up observations are planned to truly determine what occurred in this exceptional object.
Curriculum topics to be considered
Stellar life cycle
Electromagnetic spectrum
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