The Hubble telescope records the farthest star ever observed: 12.9 billion light years away

The star Eärendel, which in Old English means rising light, formed 900 million years after the Big Bang, in the early age of the cosmos.

The Hubble Space Telescope  has found the farthest star ever observed to date, about 12.9 billion light-years away.

The star, nicknamed Eärendel (rising light) by astronomers, emitted its light in the first billion years of the universe. It’s a significant jump beyond Hubble’s previous distance record, in 2018, when it detected a star around 4 billion years after the Big Bang.

How did you detect it?

“We hardly believed it at first, it was much farther away than the previous highest and most distant redshift star,” said astronomer Brian Welch of Johns Hopkins University in Baltimore, lead author of the paper describing the discovery , which is published in the journal Nature on March 30.

The discovery was made from data collected during Hubble’s RELICS (Reionization Lensing Cluster Survey) program , led by co-author Dan Coe at the Space Telescope Science Institute (STScI), also in Baltimore.

Hubble got a boost from peering through space warped by the mass of the huge galaxy cluster WHL0137-08 , an effect called gravitational lensing.

Eärendel was aligned on or very close to a ripple in the fabric of space created by the cluster’s mass, which boosted its light enough to be detected by Hubble.

The research team estimates that Eärendel is at least 50 times the mass of our Sun and millions of times brighter, rivaling the most massive known stars .

Astronomers expect Eärendel to remain greatly enlarged for years to come. It will be observed by NASA’s James Webb Space Telescope . Webb’s high sensitivity to infrared light is needed to learn more about Eärendel, because its light is stretched (redshifted) to longer infrared wavelengths due to the expansion of the universe.

Eärendel ‘s composition will be of great interest to astronomers, because it formed before the universe became filled with the heavy elements produced by successive generations of massive stars. If follow-up studies find that Eärendel is only made up of primordial hydrogen and helium, it would be the first evidence for the legendary Population III stars, which are supposed to be the first stars born after the Big Bang. While the probability is small, Welch admits it’s tempting nonetheless.