Research

On the border of our galaxy discovered the "impossible star"

Inside the halo of our Milky Way galaxyastronomers have discovered the tiny, ancient star J0023 + 0307. At first glance it may seem that for its age and location it is a completely ordinary star. However, after studying the object more closely, a group of international researchers found out one very interesting detail - the object did not have a carbon trace. It is so unusual that the scientists who investigated it stated that such a star simply should not exist. A study of scientists published in the journal Astrophysical Journal Letters.

Now they have discovered another amazingfeature of this object. It turned out that the star has a high content of lithium. In itself, this circumstance is not unusual for old stars and is quite common, however, according to researchers, the object J0023 + 0307 was formed in the first 300 million years after the Big Bang, immediately after the very first generation of stars began to die . And here begins the oddities.

"This primitive star has a high contentlithium. And it is quite possible that this lithium is related to the primary lithium, which was formed after the Big Bang, ”says astronomer David Aguado of the University of Cambridge.

When about 13.8 billion years ago the universejust formed, naturally formed only the lightest elements. Among them are hydrogen and helium, as well as a very small amount of lithium and beryllium. The process by which these elements are formed from the primary sea of ​​neutrons, protons, electrons, positrons, photons and neutrinos is called the Big Bang nucleosynthesis.

Heavy items in turn appeared later,formed inside the first stars under the influence of enormous pressure and temperature. When the first generation of stars began to die, these elements were thrown into outer space and captured by clusters of new young stars. This fact allows astronomers to quite accurately determine the age of a particular star. For example, if a star does not contain a large number of heavy elements (stars with low metal content or EMP), then this is a bright sign that the star was formed at a time when there were simply no such substances in the universe. The study J0023 + 0307 showed that it contains iron a thousand times less than that of our Sun, which makes it one of the stars with the lowest iron content among known stars.

Despite this circumstance, lithium contains approximately as much in it as that of other kindred stars. And this is very unusual.

"The lithium content in this primitive starsimilar to its volumes in other low-iron stars located in the halo of our galaxy. And as a rule, this content has a constant value, regardless of the content of other metals in the star, ”says astronomer Jonai González Hernández of the Canary Institute of Astrophysics (Spain).

In ordinary stars, where necessary for the synthesisHydrogen temperature in the core reaches 2.5 million degrees, lithium is simply destroyed. There have been cases when larger stars had a certain amount of lithium inside the colder, outer layers of the atmosphere of the star. But in small, hot stars, lithium had never met before.

Researchers speculate thatthe temperature of the ancient stars with low metal content is lower than that of younger ones. It is possible that J0023 + 0307 contains lithium, which was formed during the Big Bang nucleosynthesis. If this assumption is true, then future research in this direction will shed light on the main riddle of the Universe - the secret of its appearance.

Subscribe to our Yandex. Dzen. Every day there are published materials that do not fall on the site.