Astronomers have discovered a blockbuster celestial entity so unusual they named it the ‘Barbenheimer Star’.
Skywatchers from the Sloan Digital Sky Survey (SDSS) have uncovered evidence for an enormous ancient star that exploded in a way previously thought impossible; resulting in an unusual pattern of elemental ashes that left behind a trail of evidence still visible billions of years later.
SDSS believe the star, scientific name J0931+0038, could have been at least 50 to 80 times the mass of our Sun. It formed from the supernova remnant of whatever star was there before.
SDSS say: “In fact, that ancient supernova must have been so massive that astronomers are surprised it could happen at all – previous theories predicted that such big stars should collapse straight into black holes, without creating a supernova first.
“So its unusual composition means that the star that was there before must have also been highly unusual.”
Alex Ji of the University of Chicago and SDSS, the lead author of the study, says: “We’ve never seen anything like this. Whatever happened back then, it must have been amazing.
“We nicknamed it the ‘Barbenheimer Star’ for its spectacular nucleosynthesis.”
The humourous moniker is a reference to the headline-making blockbuster performance of the thematically opposed Barbie and Oppenheimer films released in 2023.
Nucleosynthesis is the creation of new atomic nuclei, the centers of atoms that are made up of protons and neutrons. Nucleosynthesis first occurred within a few minutes of the Big Bang.
Keith Hawkins of the University of Texas at Austin, the Scientific Spokesperson for the SDSS collaboration, says: “The Universe directed this movie, we are just the camera crew. We don’t yet know how the story will end.”
The team did not see the Barbenheimer Star directly. Instead, they followed the trail back in time using a process called “stellar archaeology.”
Just as archaeologists use evidence found in the present to reconstruct the past, astronomers use evidence found in today’s stars to reconstruct conditions in the ancient universe.
Today’s stars are like chemical time capsules: they preserve what a piece of the universe was like when the star was born.
The trail of evidence began with a star that, at first glance, appears unremarkable. The star, called J0931+0038, is a distant, bright red star captured in an SDSS image way back in 1999.
Twenty years later, the SDSS telescope turned once again to the star – “this time in technicolor,” say SDSS.
The SDSS Milky Way Mapper program observed the star’s spectrum, which measures how much light the star gives off at different wavelengths.
A spectrum can reveal many things about a star, such as its temperature and chemical composition – and it was chemistry that first led Ji and his team of stellar archaeologists to notice J0931+0038.
Stars are mostly made of hydrogen and helium, but they also incorporate some of the heavier elements, which were created in previous generations of stars and released into the universe in supernova explosions. These heavier elements show up as prominent valleys in a star’s spectrum.
The SDSS spectrum indicated that J0931+0038 had an unusually low amount of magnesium, prompting further follow-up from the Magellan telescopes in Chile.
When Ji and colleagues first viewed the follow-up spectrum of J0931+0038, they were amazed.
“As soon as I saw the spectrum, I immediately emailed the rest of the team to talk about how to learn more,” Ji said.
Several things made the star different from other stars: low abundances of elements with odd numbers on the periodic table like sodium and aluminum; a large amount of elements close to iron in the periodic table like nickel and zinc; and an overabundance of heavier elements like strontium and palladium.
“We sometimes see one of these features at a time, but we’ve never before seen all of them in the same star,” says Jennifer Johnson of the Ohio State University, another member of the stellar archaeology team.
“Amazingly, no existing model of element formation can explain what we see,” says Sanjana Curtis of the University of California, Berkeley, co-lead of the published study. “It’s not just, ‘oh, you can tweak something here and there and it’ll work out – the whole pattern of elements looks almost seems self-contradictory.”
Produced in association with SWNS Talker
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