The oldest solar twin allowed researchers to peer into our Sun's future.
The star, called HIP 102152, is about four billion years older than our galaxy's Sun. It is located 250 light-years away, an European Southern Observatory (ESO) press release reported.
Researchers also have the opportunity to observe the connection between a star's age and its lithium content.
"For decades, astronomers have been searching for solar twins in order to know our own life-giving Sun better. But very few have been found since the first one was discovered in 1997. We have now obtained superb-quality spectra from the VLT and can scrutinize solar twins with extreme precision, to answer the question of whether the Sun is special," team leader, Jorge Melendez, said.
The chemical composition of the distant star is very similar to that of Earth's Sun, meaning the HIP 102152 could host other rocky planets. Both stars show a "deficiency of the elements that are abundant in meteorites and on Earth," which led researchers to the idea.
HIP 102152, located in the constellation of Capricornus (The Sea Goat), is the oldest -known solar twin. It is 8.2 billion years old, which is nearly twice the age of our own Sun.
The team observed HIP 102152 through ESO's Very Large Telescope (VLT). They split the star's light into color-categories so they could determine the chemical composition.
"One issue we wanted to address is whether or not the Sun is typical in composition," Melendez said. "Most importantly, why does it have such a strangely low lithium content?"
Scientists have often wondered why some stars contain more of the element than others. Lithium is believed to have been created in the Big Bang, and is the third element on the periodic table.
These new observations suggest a star's lithium content is related to its age. If the theory is correct, our Sun has only one percent of the lithium content it started out with.
"We have found that HIP 102152 has very low levels of lithium. This demonstrates clearly for the first time that older solar twins do indeed have less lithium than our own Sun or younger solar twins. We can now be certain that stars somehow destroy their lithium as they age, and that the Sun's lithium content appears to be normal for its age." TalaWanda Monroe, lead author of the paper, said.
