A newly discovered star, named J0524-0336, has left astronomers scratching their heads and may provide fresh insights into the life cycle of stars.
This discovery, reported in The Astrophysical Journal by Assistant Professor of Astronomy Rana Ezzeddine and UF alumnus Jeremy Kowkabany, along with their collaborators, reveals a star that defies current theories about how stars evolve and form chemical elements.
Typically, as stars burn and age, they gradually lose lighter elements like lithium, which gets replaced by heavier elements such as carbon and oxygen.
However, when Ezzeddine’s team analyzed J0524-0336, they found something astonishing: the star has an unusually high amount of lithium—much more than is expected for a star of its age, or even any star at any stage of its life.
J0524-0336 was discovered during a survey aimed at finding older stars in our galaxy, the Milky Way.
This star is in an advanced stage of its life, known as an evolved star, which means it has grown unstable, becoming much larger and brighter than stars typically are. In fact, it is about 30 times the size of our sun.
To figure out what elements J0524-0336 is made of, the researchers used a technique called spectroscopy.
This method involves attaching a spectrograph to a telescope, which then splits the star’s light into a spectrum, much like a rainbow. By studying the dark spots on this spectrum, scientists can determine the presence and quantity of different elements in the star.
“We discovered that J0524-0336 contains 100,000 times more lithium than the sun currently has,” said Ezzeddine.
“This amount is surprising and challenges the existing models of how stars evolve. It might suggest that there is a previously unknown process that allows stars to either produce or retain lithium.”
The team has come up with a few possible explanations for this unusual lithium content. One idea is that J0524-0336 might be in a phase of star evolution that hasn’t been observed before.
Another possibility is that the star recently interacted with another celestial body, such as a planet or another star, which could have caused it to absorb a large amount of lithium.
As stars age, they can sometimes engulf nearby planets or stars, which might explain the sudden increase in lithium.
Ezzeddine and her team believe that both of these explanations could be true, but more research is needed to confirm this.
They plan to continue studying J0524-0336 to track any changes in its composition over time.
They also hope to observe the star using different types of light, like infrared and radio waves, to see if it is ejecting any material.
“If we observe a build-up of dust around the star, it could indicate that the star is losing mass due to a recent interaction,” Ezzeddine explained. “But if we don’t see this, it might mean that something new and unexplained is happening inside the star itself.”
This ongoing research could help us better understand not only this mysterious star but also the complex processes that govern the life and evolution of all stars.
Source: University of Florida.
