Cork astronomer’s major scientific discovery
A Cork researcher has played a crucial role in a groundbreaking discovery about the creation of elements in space.
An international team of scientists used various space and ground-based telescopes, including NASA's James Webb Space Telescope (JWST), to study an exceptionally bright gamma-ray burst known as GRB 230307A. They identified a neutron star merger as the source of this explosion, which led to the creation of the burst.
Scientists have long theorised that the explosions caused by two neutron stars merging with each other – otherwise known as a kilonova – should create the pressure cooker conditions in which many elements heavier than tellurium are created. However, observing such events and proving they create these 'heavy' elements has proven elusive – until now.
By utilising the James Webb Space Telescope's remarkable sensitivity, astronomers captured the first mid-infrared spectrum from space of a gamma-ray burst, likely resulting from a kilonova. This marked the first time the Webb telescope directly witnessed the creation of heavy elements in such an event.
The research results were published in the prestigious scientific journal Nature. The study suggests that other elements close to tellurium on the periodic table, like iodine, which is essential for life on earth, are also likely to be present among the kilonova’s ejected material.
Dr Mark Kennedy, an astronomer based at University College Cork’s School of Physics, is co-author of the paper, and took data with the European Southern Observatory’s New Technology Telescope in Chile which led to the discovery of the optical counterpart to the kilonova.
This discovery is what led to the proposal for JWST observations.
Dr Kennedy explained: “Not every gamma-ray burst produces an explosion that we can study with JWST, and the light from those that do can fade very rapidly. This means every second - between when NASA’s Fermi Gamma-ray Space Telescope detects a gamma-ray burst and when we point our telescopes on Earth at where we think the bust occurs - counts.
“This explosion occurred in the very southern part of the night sky, making it impossible to observe with most of our ground-based facilities.
“Fortunately, I was observing with a telescope in Chile - remotely from my dining room in Cork - several hours after the explosion reached us here on Earth and found a new object had appeared in the night sky right where the burst had come from.
“This excitement rippled out through the astronomical community as we realised we might be witnessing a kilonova. In the following weeks, our group submitted proposals to use JWST to study such an event for the first time, with the results speaking for themselves,” the Cork researcher said.
Lead author of the study, Andrew Levan from Radboud University in the Netherlands and the University of Warwick in the UK, explained the great significance of this discovery. “Just over 150 years since Dmitri Mendeleev wrote down the periodic table of elements, we are now finally in the position to start filling in those last blanks of understanding where everything was made, thanks to Webb,” he concluded.