03 April 2022
Space scientists say they have identified the most distant star ever recorded.
Astronomers made the discovery with the Hubble Space Telescope, operated by the American space agency NASA.
Researchers estimated the star was 50 to 100 times the mass of our sun, and millions of times brighter.
It takes billions of years for light from distant stars to reach Earth. The team said the star's light is believed to have traveled for 12.9 billion years before reaching our planet. This means the star would have existed when the universe was about seven percent of its current age.
A member of the research team, Brian Welch, named the extremely hot and bright star Earendel. That is an Old English name that means morning star or rising light.
"We're seeing the star as it was about 12.8 billion years ago, which puts it about 900 million years after the Big Bang," Welch said. He is a doctoral student at Johns Hopkins University in the state of Maryland. He was the lead writer of a study describing the finding in the publication Nature. The Big Bang is the explosion that many scientists believe created the universe.
"We definitely just got lucky," Welch said of the discovery. Although scientists on Earth can now see its light, Earendel itself surely no longer exists, Welch said. This is because such huge stars have short lives. The star probably existed for a few hundred million years before dying in a supernova explosion, Welch added.
The previous record-holder is named Icarus. It is a similar, huge star observed by Hubble. It is believed to have formed 9.4 billion years ago.
In both cases, astronomers were able to see the light from the star because of an effect known as gravitational lensing. It is the result of gravity from groups of closer galaxies between Earth and the star. The gravity acts like a lens to magnify distant objects in the background.
Hubble has observed the light from galaxies that date to about 400 years after the Big Bang. But individual stars at such great distances are not possible to identify.
"Usually they're all smooshed together," said NASA astrophysicist Jane Rigby, who took part in the study. She said, "Here, nature has given us this one star — highly, highly magnified, magnified by factors of thousands — so that we can study it."
"It's such a gift really from the universe," Rigby added.
Welch said that Earendel may have been the main star in a two-star system, or possibly even a triple- or quadruple-star system. He noted that there is a small chance it could be a black hole. But he added that observations gathered in 2016 and 2019 suggest that is not the case.
The researchers said NASA's James Webb telescope should help them learn more about the star and its parent galaxy. The Webb telescope is 100 times more powerful than Hubble.
Rigby said that by studying stars: "We are literally understanding where we came from because we're made up of some of that stardust."
I'm Bryan Lynn.
The Associated Press and Reuters reported on this story. Bryan Lynn adapted the reports for VOA Learning English.
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Words in This Story
definite – adj. certain, fixed and not likely to change
supernova – n. a star that has exploded, strongly increasing its brightness for a period of time
lens – n. a piece of equipment, made of glass or plastic, with a curved surface that is used to make images larger or cleaner
magnify – v. to make something appear larger
smoosh – v. crush, flatten or move close together
factor – n. a particular level on some systems of measurement
literally – adv. using the real or original meaning of a word or phrase
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