File:NASA’s Webb Makes First Detection of Heavy Element From Star Merger (labeled) (53284913386).png

Three explosions, two stars, and a rare discovery. Webb recently detected tellurium, an element rarer than platinum on Earth, in the explosive aftermath of two neutron stars merging.

The pair were once two stars tied together by gravity in a distant spiral galaxy. First one star, then the other exploded. As their cores collapsed into dense remnants, they became neutron stars. These two explosions would launch the pair out of their home galaxy — 120,000 light-years away. Several hundred million years later, the neutron stars violently merged, triggering both a gamma-ray burst and a kilonova.

Gamma-ray bursts are extremely bright, short blasts of the most energetic form of light. This gamma-ray burst, GRB 230307A, was first detected by the Fermi Gamma-Ray Space Telescope in March 2023. It’s the second brightest gamma-ray burst ever observed!

Accompanying the gamma-ray burst was a kilonova emitting optical and infrared light. A team of telescopes, including NASA’s Swift Observatory, helped identify the kilonova from the ground and from space. With its highly sensitive infrared eye, Webb helped scientists find out the home galaxy of the two neutron stars.

Kilonovas were long thought to create many of the heavier elements we're familiar with, like gold in our jewelry or iodine in our blood. Webb shows a clear detection of tellurium in its data — the first time a heavy element has been detected from a kilonova. With this discovery, astronomers believe Webb can find even more kilonovas and evidence of neutron star mergers creating heavy elements: <a href="https://www.nasa.gov/missions/webb/nasas-webb-makes-first-detection-of-heavy-element-from-star-merger/" rel="noreferrer nofollow">www.nasa.gov/missions/webb/nasas-webb-makes-first-detecti...</a>

Image credit: NASA, ESA, CSA, STScI, Andrew Levan (IMAPP, Warw)

This image: This image from Webb’s NIRCam (Near-Infrared Camera) instrument highlights GRB 230307A’s kilonova and its former home galaxy among their local environment of other galaxies and foreground stars. The neutron stars were kicked out of their home galaxy and traveled the distance of about 120,000 light-years, approximately the diameter of the Milky Way galaxy, before finally merging several hundred million years later.