Supernova science: What chemically happens when a star explodes? -

COLUMBUS, Ohio — An exploding supernova may have unveiled some chemical secrets behind the formation of our universe. Data taken from the James Webb Space Telescope allowed astrophysicists to observe whether chemical elements were released into the surrounding cosmos after the massive explosion.

The explosion occurred in a faraway spiral galaxy about 40 million light-years from Earth. Despite its extreme distance, it has been a popular area of exploration among scientists looking to understand how star-forming nebulas form and evolve. The explosion was a carbon-oxygen white dwarf star classified as a Type 1a supernova.

“White dwarf explosions are important to the field of cosmology, as astronomers often use them as indicators of distance,” says Michael Tucker, a fellow at the Center for Cosmology and AstroParticle Physics at The Ohio State University and co-author of the study, in a university release. “They also produce a huge chunk of the iron group elements in the universe, such as iron, cobalt, and nickel.”

Light elements like hydrogen and helium were created after the Big Bang, but heavier elements are made only through thermonuclear reactions that happen inside a supernova. Understanding how these explosions impact the distribution of iron elements around the universe could give astronomers a better idea of the chemical formation of the universe.

Hubble Telescope captures supernova — Astronomers using NASA’s Hubble Space Telescope captured the quick, fading celebrity status of a supernova, the self-detonation of a star. (Image credit: NASA, ESA, and A. Riess (STScI/JHU) and the SH0ES team; acknowledgment: M. Zamani (ESA/Hubble))

“As a supernova explodes, it expands, and as it does so, we can essentially see different layers of the ejecta, which allows us to probe the nebula’s core,” explains Tucker.

The event happens through a process called radioactive decay. This is when an unstable atom emits energy to become more stable. Supernovas release radioactive high-energy photons. The scientists’ current focus is on how the supernova causes the isotope cobalt-56 to decay into iron-56.

For years, astronomers have been stumped on what effect the decay of cobalt-56 has on its surroundings. Do the fast-moving particles made from the reaction leak into the galaxy, or are they held back through magnetic fields created by supernovas?

Supernova remnants — The lower two of these shell-like features are supernova remnants, with SNR G1.0-0.1 on the left and SNR G0.9+0.1 on the right. The uppermost shell is the Sagittarius D HII region, a site of recent star formation. SNR G0.9+0.1 has a pulsar wind nebula at its centre, showing a tangled complex of radio emission. Polar outflows from this nebula appear to be distorting the shell of the supernova, particularly towards the north. (CREDIT: I. Heywood, SARAO, Rhodes/ SWNS)

The data the Webb Telescope captured allowed astrophysicists to confirm that the materials released from the supernova didn’t escape the confines of the explosion.

“This study validates almost 20 years’ worth of science,” Tucker explains. “It doesn’t answer every question, but it does a good job of at least showing that our assumptions haven’t been catastrophically wrong.”

The study is published in The Astrophysical Journal Letters.