The brightest gamma-ray burst ever detected, GRB 221009A, occurred on October 9, 2022. Lasting for hundreds of seconds, it was 70 times brighter than any previous burst and had an unprecedented energy level. Nicknamed "BOAT," it displayed a peculiar structure with no clear edge, unlike typical bursts that resemble ice cream cones.
While the burst's brightness resulted from its direct alignment with Earth, its exceptional properties defy existing predictive models. The burst's energy and structure originate from the massive star that triggered it, leaving behind a black hole 30 times the Sun's mass. Varying properties of the exploding star, such as size, mass, density, or magnetic field, can account for the different jet structures and energy. Astronomers believe that the burst interacted with the star's material, generating shock-heated gas waves detected in its afterglow. Continued observations of GRB 221009A will shed light on its fading process and potential environmental interactions, and provide further details about the originating galaxy and star.