Hubble Space Telescope Discovers the Farthest Star Ever Seen
NASA’s Hubble Space Telescope has established a new record by detecting the light of a star that lived during the first billion years of the universe’s birth in the big bang, making it the farthest distant individual star ever observed.
The finding is a huge step back in time from the previous single-star record holder, which Hubble detected in 2018. According to scientists, that star existed when the universe was roughly 4 billion years old, or 30 percent of its present age, during a phase known as “redshift 1.5.” Scientists use the word “redshift” to explain how light from distant objects is stretched or “shifted” to longer, redder wavelengths as it travels toward us as the universe expands.
The newly found star is so far away that its light took 12.9 billion years to reach Earth, arriving at redshift 6.2, when the universe was still expanding was just 7% of its present age. Clusters of stars imprisoned within early galaxies are the tiniest objects ever discovered at such a great distance.
“We almost didn’t believe it at first because it was so far out from the previous most-distant, greatest redshift star,” said astronomer Brian Welch of Johns Hopkins University in Baltimore, lead author of the study revealing the finding, which was published on March 30 in the journal Nature. The finding was found using data from Hubble’s RELICS (Reionization Lensing Cluster Survey) program, which was directed by NASA’s Goddard Space Flight Center co-author Dan Coe.
“At these distances, entire galaxies seem like little smudges, with the light from millions of stars mixing together,” Welch explained. “Gravitational lensing enlarged and warped the galaxy harboring this star into a lengthy crescent that we termed the Sunrise Arc.”
Welch concluded that one aspect of the galaxy is an extraordinarily magnified star he named Earendel, which means “dawn star” in Old English. The finding has the potential to usher in a hitherto unknown era of extremely early star creation.
“Because Earendel existed so long ago, it may not have had all of the same basic ingredients as the stars surrounding us now,” Welch stated. “Studying Earendel will provide us with a doorway into a time in the cosmos that we are unfamiliar with, but which led to all we know today.” “It’s like if we’ve been reading a great intriguing novel, but we just got to the second chapter, and now we’ll be able to see how it all began,” Welch explained.
Confirmation with Webb
According to astronomers, Earendel will continue to be strongly magnified for many years to come. It will be seen by NASA’s James Webb Space Telescope. Because the universe’s expansion causes Earendel’s light to be stretched (redshifted) to longer infrared wavelengths, Webb’s exceptional sensitivity to infrared light is necessary to learn more about it.
“We intend to confirm Earendel is a star, as well as measure its brightness and temperature, using Webb,” Coe added. These specifics will help to identify its kind and stage in the stellar lifetime. “We also hope to discover that the Sunrise Arc galaxy is deficient in heavy metals that emerge in future generations of stars.” “This would imply that Earendel is an unusual, big, metal-poor star,” Coe explained.
Astronomers will be attracted by Earendel’s composition since it developed before the cosmos was filled with the heavy elements generated by subsequent generations of massive stars. If additional investigation reveals that Earendel is entirely composed of primordial hydrogen and helium, it will be the first confirmation of the mythical Population III stars, which are supposed to be the very first stars to emerge after the big bang. Even if the odds are tiny, Welch admits that the concept is alluring.
“With Webb, we may be able to view stars even further away than Earendel, which would be incredible,” Welch added. “We’ll go back as far as we can.” I’d love to see Webb shatter Earendel’s long-distance record.”
The Hubble Space Telescope is a NASA-ESA international collaboration project (European Space Agency). The telescope is managed by NASA’s Goddard Space Flight Center in Greenbelt, Maryland. Hubble science operations are managed by the Space Telescope Science Institute (STScI) in Baltimore, Maryland. The Association of Universities for Research in Astronomy in Washington, D.C. manages STScI for NASA.