Asteroid debris in the atmosphere of a dead white dwarf star could help astronomers find and measure the missing lithium in the universe.
Measurements of lithium in stars like our sun have never been added to the amount that scientists expect to exist, indicating that there is much more than we can find.
The Big Bang, the main explanation for how the universe began 13.8 billion years ago, produced three elements: hydrogen, helium, and lithium.
Of the three elements, lithium is the biggest puzzle. But the new study by astronomers at the University of North Carolina provides clues to track its evolution.
Finding traces of an element in the rocky remnants of an asteroid in the atmosphere of a nine billion-year-old white dwarf could help scientists estimate the total amount of lithium in the universe, as this indicates that it may be dispersed into rocky bodies.
It is the first time that the hard-to-find element has been identified in the burning remains of a dead star, according to University of North Carolina researchers.
Despite its many uses on Earth to power electronics and stabilize moods, scientists have been baffled by the paradox known as the “cosmic lithium problem.”
Nobody knows exactly how much lithium is in the universe, but these new findings mean that white dwarf stars can be used to estimate the total amount.
This discovery was made possible using a unique spectrometer mounted on the Southern Astrophysical Research Telescope.
The study author, astrophysicist Christopher Clemens, led the design of the Goldman Spectroscopy, which measures the amount of light emitted by a white dwarf.
White dwarfs are the nuclei remaining after the death of stars, and they can be surrounded by rocky worlds. The high surface gravity of these stars should cause elements heavier than hydrogen and helium to sink rapidly below the surface.
However, some “polluted” white dwarf stars are showing evidence of heavier elements on their surfaces, and are believed to be the result of the recent accumulation of rocky objects.
In the study, the researchers described the discovery of the shattered remnants of large asteroid-like bodies in the atmosphere of two very old white dwarfs.
The planets of these dead stars formed for the first time nine billion years ago – our sun and the planets formed only 4.6 billion years ago.
The team measured the chemical composition of asteroids, and for the first time identified and measured both lithium and potassium from a rocky object outside the solar system.
The theory predicts that lithium predominantly formed in the first five minutes after the Big Bang. Its later history differs from other elements and is more mysterious, because lithium is consumed by nuclear reactions in stars.
Finding them in white dwarf stars provides a record of the original rocky objects that formed nine billion years ago – and thus the abundance of lithium in the galaxy at the time they formed – during the first few billions of the universe.
The miners noted that accumulated objects such as those that contaminated this star “represent an alternative to the ancient stars to gain insight into abundance.” [الليثيوم] Primitive, the first epochs of chemical fertilization in our galaxy, and the characteristics of the ancient exoplanet. “
Ultimately, with enough of these white dwarfs over which asteroids have fallen, we will be able to test to predict how much lithium was formed in the Big Bang.
The results are published in the journal Science.
Source: Daily Mail