Space Telescopes Capture Rare Cosmic Event 1 Billion Light Years Away, Shedding Light on Formation of Unusual Elements
Astronomers have witnessed an extraordinary event that occurred 1 billion light years away, shedding light on the formation of rare heavy elements. The event involved a violent collision between two neutron stars that were expelled from their home galaxy.
The cataclysmic collision unleashed a burst of gamma rays that was over 1 million times brighter than the Milky Way. The explosion also ejected material into space that gave rise to rare elements such as tellurium, actinides, and lanthanides. It is believed that more common elements like iodine and thorium were also created during this event.
The James Webb space telescope, for the first time, enabled astronomers to observe this cosmic spectacle known as a kilonova. Through infrared signatures, researchers were able to identify the elements produced in the collision.
The study, published in the journal Nature, reveals that while lighter elements are typically formed through fusion in stellar cores or in stellar explosions, heavier elements are forged in the energetic environment of neutron star collisions.
Andrew Levan, professor of astrophysics at Radboud University in the Netherlands, said, “For the first time we have evidence of these particular kinds of elements being formed in these mergers. It’s 150 years since we’ve had the periodic table, and we still don’t know where a good number of elements come from. One of the things we’re trying to do is fill in those gaps.”
Neutron stars are incredibly dense and compact objects, similar in mass to the sun but with a size comparable to that of a city. Astronomers detected an intense burst of gamma rays in March, which alerted them to the potential collision between neutron stars.
By utilizing a combination of ground- and space-based detectors and telescopes, researchers were able to locate the source of the radiation burst and subsequently directed the James Webb space telescope to observe its aftermath.
Over the course of several days, the color of the emitted light from the collision transitioned from blue to red, indicating a kilonova. The neutron stars had apparently been expelled from a nearby galaxy before merging 120,000 light years away, several hundred million years later.
Although the collision likely resulted in the creation of a new black hole, it also propelled vast quantities of neutrons and other material into space. Through a process called rapid neutron capture, these high-energy neutrons bombarded atomic nuclei, causing them to become unstable and transform into heavier elements through radioactive decay.
Kilonovae events are extremely rare, with scientists having observed only one previous event in sufficient detail to infer the elements formed during the explosion. While elements like iron and nickel are typically created in supernovae, more violent neutron star collisions offer favorable conditions for the production of heavier elements.
Andrew Levan emphasized, “About half of the elements heavier than iron are probably made in these events. We hoped to see this, but you never quite know what you’re going to get.”
This groundbreaking research provides valuable insights into the origin of elements and fills gaps in our understanding of the periodic table. The observations made possible by the James Webb space telescope contribute to our knowledge of the universe’s mechanisms for creating diverse and rare elements.