NASA reveals the first image of the farthest star in the universe

The James Webb Space Telescope has followed Hubble's observations of the most distant star detected in the very distant universe, in the first billion years after the Big Bang.

Webb's NIRCam (Near Infrared Camera) instrument reveals that the star Earendel, discovered by Hubble in 2022, is a massive B-type star, more than twice as hot as our Sun, and about a million times more luminous.

Earendel is located in the Arc of Dawn galaxy and is only detectable due to the combined power of human technology and nature through an effect called gravitational lensing.. Both Hubble and Webb were able to detect Earendel due to its lucky alignment behind a ripple in space-time created by the huge galaxy cluster WHL0137-08.

The galaxy cluster, located between us and Eärendel, is so massive that it warps the fabric of space itself, producing a magnifying effect, allowing astronomers to peer through the cluster like a magnifying glass, NASA reports.

While other features in the galaxy appear multiple times due to gravitational lensing, Earendel only appears as a single point of light, even in Webb's high-resolution infrared images.. Based on this, astronomers determine that the object is magnified by a factor of at least 4,000 and therefore extremely small: the most distant star ever detected, observed 1 billion years after the Big Bang.

The previous record holder for the most distant star was detected by Hubble and observed around 4 billion years after the Big Bang.. The astronomers did not expect Webb to reveal any companions to Eärendel, as they would be close together and indistinguishable in the sky.

However, based solely on Eärendel's colors, astronomers believe they see hints of a cooler, redder companion star.. This light has been stretched by the expansion of the universe to longer wavelengths than Hubble's instruments can detect, so it was only detectable with Webb.

Webb's NIRCam also shows other remarkable details in the Arc of Dawn, which is the largest galaxy yet detected in the first billion years of the universe.. Features include young star-forming regions and older established star clusters as small as 10 light-years across.

On either side of the wrinkle at maximum magnification, which runs through Earendel, these features are reflected in the gravitational lens distortion. The star-forming region appears elongated and is estimated to be less than 5 million years old.

The smaller dots on either side of Eärendel are two images of an older, more established star cluster, estimated to be at least 10 million years old.. Astronomers determined that this star cluster is gravitationally bound and is likely to persist to this day.. This shows us what the globular clusters of our own Milky Way might have looked like when they formed 13 billion years ago.

The astronomers are currently analyzing data from Webb's NIRSpec (Near-Infrared Spectrograph) instrument observations of the Dawnbow and Earendel galaxy, which will provide precise composition and distance measurements for the galaxy.

Since Hubble's discovery of Earendel, Webb has detected other very distant stars using this technique, though none as far away as Earendel.. The discoveries have opened up a new realm of the universe for stellar physics and a new subject for scientists studying the early universe, where galaxies were once the smallest detectable cosmic objects. The research team is hopeful that this could be a step towards the eventual detection of one of the first generations of stars, composed solely of the raw ingredients of the universe created in the big bang: hydrogen and helium.