Nova Centauri exploded in 2013, catching the eye of scientists who have been studying it at the European Southern Observatory (ESO).
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Astrophysicists have long been puzzled about why there is so little lithium, an element created in the Big Bang, in older stars and so much of the stuff in the younger stellar population.
Using telescopes in Chile, an Italian team focused on Nova Centauri 2013, a supernova whose light reached Earth two years ago. A nova occurs in binary star systems where a white dwarf star pulls hydrogen from its binary partner. Certain models of the Big Bang theory allowed astronomers to calculate fairly accurately how much lithium should be present in the universe.
In the 1970s, the attention of astronomers changed its course to novae as being the culprit. However, astronomers have observed a greater abundance of lithium in younger stars than older stars, indicating there must be another production mechanism in the modern universe. It’s a major finding that potentially solves a mystery in how the galaxy evolves chemically. But they found the levels in the cluster similar to those in the Milky Way, leaving the puzzle unsolved. But the first time that there was clear evidence of lithium in the nova to prove the hypothesis, the scientists found. Back in 2012, they watched as a planet was sucked in by a red giant that contained a lot of lithium.
The discovery of lithium being expelled at some 2 million kilometers (1.24 million miles) per hour in Nova Centauri could, when extrapolated to the billions of other novae that have exploded in the Milky Way’s history, explain the unexpectedly large amount of lithium in our galaxy, the ESO said. It is thought that lithium was mainly produced just after the Big Bang. In depth simulations of chemical enrichment of the galaxy demonstrated the novae were needed to explain the overabundance of lithium in young stellar populations. “If we imagine the history of the chemical evolution of the Milky Way as a big jigsaw, then lithium from novae was one of the most important and puzzling missing pieces”, said co-author Massimo Della Valle from Osservatorio Astronomico di Capodimonte, Naples, Italy.
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“It is very exciting”, said Luca Izzo, “to find something that was predicted before I was born and then first observed on my birthday in 2013!”
