This explosion, which transpired on March 7, ranks as the second most luminous gamma-ray burst ever recorded by telescopes in over half a century. It shone with a brilliance surpassing one million times that of the entire Milky Way Galaxy. Gamma-ray bursts are fleeting yet intense flashes of the universe’s most energetic form of light.
This specific burst, labeled GRB 230307A, likely originated from the merger of two neutron stars, which are the ultra-dense remnants left after a star undergoes a supernova. This union not only emitted the gamma-ray burst but also triggered a kilonova. Kilonovae are rare cosmic events that arise when a neutron star merges with another neutron star or a black hole. This discovery was detailed in a recent publication in the journal Nature.
Andrew Levan, the lead study author and astrophysics professor at Radboud University in the Netherlands, expressed the significance of this event. He highlighted that this was the first instance where the aftermath of a kilonova was observed using the James Webb Space Telescope.
Several observatories, including NASA’s Fermi Gamma-ray Space Telescope, Neil Gehrels Swift Observatory, and the Transiting Exoplanet Survey Satellite, observed the burst and traced its origins back to the neutron star merger. The Webb telescope was instrumental in identifying the chemical signature of tellurium in the explosion’s aftermath.
Tellurium, a scarce metalloid, finds applications in coloring glass and ceramics and plays a role in producing rewritable CDs and DVDs. Astronomers anticipate that other elements neighboring tellurium on the periodic table, such as iodine (essential for many life forms on Earth), might also be present in the material expelled by the kilonova.
Astronomers have long theorized that neutron star mergers serve as cosmic factories, producing rare elements heavier than iron. However, gathering concrete evidence has been challenging due to the rarity of kilonovae.
This gamma-ray burst’s extended duration of 200 seconds was unusual, as such long bursts are typically linked to supernovas resulting from the explosion of massive stars.
The research also delved into the history of the neutron stars before their explosive merger. These stars were once part of a binary system in a spiral galaxy. After undergoing supernovas, they were ejected from their galaxy, journeying together for 120,000 light-years before their eventual merger.
The study of stellar explosions like kilonovae in recent times is paving the way for scientists to answer questions about the formation of chemical elements, offering a deeper insight into the universe’s evolution.
Ben Gompertz, a study coauthor and assistant professor at the University of Birmingham, emphasized the transformative potential of the Webb telescope in enhancing our understanding of the cosmos.