Astronomers have taken the help of NASA's Hubble Space Telescope to determine the age of a star that has been around for many years.
Astronomers have taken crucial steps in giving an old star a "birth certificate."
"We have found that this is the oldest known star with a well-determined age," said Howard Bond of Pennsylvania State University in University Park, Pennsylvania and the Space Telescope Science Institute in Baltimore, Maryland.
According to the astronomers, the star could be as old as 14.5 billion years (0.8 billion give or take), which, if accurate is more that the age of the universe which is said to be 13.8 billion years. This is a cause of dilemma among scientists. Studies conducted at the beginning of this century showed that the star was 16 billion years old. Since scientists thought this odd, they initiated this new study.
"Maybe the cosmology (of 2000) is wrong, stellar physics is wrong, or the star's distance is wrong," Bond said. "So we set out to refine the distance.
The Hubble Space telescope found that the star has a higher than predicted oxygen-to-iron ratio, which lowers the earlier predicted age. Bond thinks that further oxygen measurement could reduce the star's age even more, because the star would have formed at a slightly later time when the universe was richer in oxygen abundance. Lowering the upper age limit would make the star unequivocally younger than the universe.
"Put all of those ingredients together and you get an age of 14.5 billion years, with a residual uncertainty that makes the star's age compatible with the age of the universe," said Bond. "This is the best star in the sky to do precision age calculations by virtue of its closeness and brightness."
Further studies to determine the age of the star more accurately are being scheduled but no certain date has been decided yet.
