Newly-discovered star could provide new insights into the evolution of stars

A recent study published in The Astrophysical Journal, under the leadership of Assistant Professor of Astronomy Rana Ezzeddine and UF alumnus Jeremy Kowkabany, has reported the discovery of a star that could redefine astronomers' comprehension of stellar evolution and chemical element formation. This finding may also point toward a previously unrecognized stage in star development.

Traditionally, it is understood that as stars undergo fusion, they deplete lighter elements such as lithium in favor of heavier ones like carbon and oxygen. However, the new star—designated J0524-0336 according to spatial coordinates—exhibits an unusually high lithium content for its age, higher than any star typically displays at any age.

J0524-0336 was uncovered by Ezzeddine during another study aimed at surveying ancient stars within the Milky Way. This star is categorized as evolved, indicating it is in the latter stages of its life cycle and becoming unstable. Consequently, it boasts a luminosity and size approximately 30 times that of the Sun.

To determine J0524-0336's elemental makeup, Ezzeddine's team employed spectroscopy. Technique involving a spectrograph attached to a telescope filtering the star's light to detect its elemental composition. Their findings show J0524-0336 possesses 100,000 times more lithium than the Sun at a comparable age, challenging prevailing theories about stellar evolution and suggesting potential unknown mechanisms of lithium production or retention.

The research team has proposed several hypotheses to explain the star's high lithium levels. It might be in an unobserved phase of stellar evolution or could have gained lithium through a recent interaction with another celestial body. Older, larger stars are thought to absorb nearby planets and stars as they age, so it’s plausible J0524-0336 absorbed a lithium-rich body. Ezzeddine believes a combination of factors may account for the lithium abundance, though further analysis is crucial.

Ezzeddine, Kowkabany, who now is a graduate student at FSU, and their team intend to conduct ongoing research on J0524-0336. They aim to monitor the star's compositional changes over time and investigate various wavelengths, including infrared and radio waves, to detect potential ejection of material from the star.

"If we observe dust build-up in the star's circumstellar disk, it would indicate a mass loss event, like a stellar interaction," Ezzeddine elaborated. "In the absence of such a disk, we could infer that an intrinsic, yet undiscovered process within the star might be responsible for the lithium enrichment."

Earlier, SSP wrote how rare fossils revealed insights into the origins of Homo floresiensis.