Observing the collision of two neutron stars led to the first near-real-time recognition of the formation of “rare earth” elements and other heavy metal elements such as silver and gold. With recent research published in NatureThe idea that kilonovae are factories of matter in the universe is reaffirmed.
An international team of scientists followed the trail of a burst of gamma rays that appeared in the sky during March 2023. The studies determined that this emission of radiation most likely came from the collision of two extremely dense stars that imploded after exhausting their nuclear fuel. .
A plan to create an antenna in space to capture gravitational waves has just been approved by the ESA.
In the wake of GRB 230307A
The gamma-ray burst, identified as GRB 230307A, occurred in a galaxy 950 million light-years from Earth. With the location and time of the kilonova located, scientists began to collect data from some of the major observatories that agreed on this point. The collision of two neutron stars was recorded for up to two full months by telescopes such as James Webb or Hubble.
The scientists involved acknowledge that it is unusual for a kilonova to be observed for more than a few days.. “To date, we have never had the opportunity to think about kilos for so long,” said Eleonora Troja, scientific co-author of the research.
Spectrographs from the James Webb Space Telescope confirmed that the cosmic shock produced elements heavier than iron through the process of neutron capture. The merger of two neutron stars released matter that was later transformed into metals and other elements of the periodic table known as the lanthanides.
Stellar nucleosynthesis: the event that creates gold and silver
Stars themselves act as factories of matter from the basic elements they are made of, such as hydrogen and helium. However, this spatial nucleosynthesis only applies to matter in the periodic table that is less heavy than iron. Extremely energetic conditions are necessary for the production of atoms from which gold, silver, cobalt or cadmium are formed.
Stellar explosions, binary system collisions or black holes are some of the extreme scenarios where this process of stellar nucleosynthesis of heavy elements has been theorized to exist. During a supernova or kilonova, the cores of elements lighter than iron quickly capture additional neutrons, leading them to transmute into another nature.
These energy events are unpredictable and short-term, and humanity cannot yet predict them. Astronomers have called them transitory events and they represent one of the priorities in space research. Sudden bursts of energy often herald the birth or disappearance of titanic objects or reveal the presence of cataclysmic events impacting galaxies.
Observing transients has led to the discovery of events such as the collision of neutron stars orbiting as a binary system, the disappearance of planets engulfed by their parent stars, the explosion of massive stars, and even colliding black holes.
