Scientists have discovered that lithium is a material that is being ejected into space once a star explodes. This could prove to be a direct indicator as to why so many younger stars in our galaxy have more lithium than expected.
The discovery was made with the aid of the MPG/ESO 2.2-m telescope at the La Silla Observatory and the ESO 0.5-m telescope at the Observatory of the Pontificia Universidad Catolica de Chile. Using these two telescopes, scientists were able to study the Nova Centauri 2013. The star’s name is a result of its explosion back in 2013 and it was deemed the brightest nova of the century.
Data collected reveals that the explosion expelled lithium at a speed of 2 million km per hour from Nova Centauri and while the quantity of lithium that was expelled is not as high as it seems, the Milky Way has a vast record of novae that have exploded over time, adding bits and pieces to the immense puzzle. This provides enough evidence as to why there is so much lithium in our galaxy.
Luca Izzo, a researcher of the Sapienza University of Rome Department of Physics, described the thought process behind the research, questions that date back to the 1970s. He mentions that lithium finds itself among the elements created during the Big Bang nucleosynthesis (BBN) and it can be easily destroyed by most astrophysical processes. The amount of lithium observed in old stellar populations is smaller than the estimated by the BBN.
“However, in younger stellar populations, the abundance of lithium can reach values larger up to one order of magnitude than the primordial one. For many years the question about was: where does it come from? “We have detected, for the first time, the presence of lithium in a nova star. This implies that nova systems (about 30 events per year in our galaxy) enrich the gas of the Milky Way through their ejecta.”
In the 1970s scientists suspected that a large portion of lithium found in Population I stars (younger stars) was an addition from older, Population II stars. Yet there was no exact conclusion up until now.
Izzo mentioned that the discovery was bound to be made sooner or later and he declared it “a satisfying conclusion” to a question that sought answers for decades. The discovery also has a secondary implication: it allows us to question the Big Bang model. A more accurate explanation concerning the creation of the Universe might be found once we understand the lithium conundrum.
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