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Webb sheds light on Earendel, the most distant star in the universe

Last year, the Hubble Space Telescope made headlines by detecting the most distant star ever seen, a luminary from the universe’s first billion years named “Earendel.” Now, NASA’s James Webb Space Telescope has uncovered mesmerizing details about this intriguing star.

“The Hubble provided us a glimpse of Earendel, but the James Webb Space Telescope is now offering us a deep dive,” said NASA. “These observations not only enlighten us about the star’s nature but also about its host galaxy, the Sunrise Arc, and possibly about the early universe itself.”

A chance discovery

Earendel is no ordinary star. Webb’s NIRCam (Near-Infrared Camera) instrument paints a portrait of a massive B-type star, sizzling at temperatures twice as scorching as our Sun and radiating with a luminosity a million times more intense. 

Situated in the Sunrise Arc galaxy, Earendel’s detection was made possible by a combination of human innovation and cosmic alignment. A serendipitous effect called gravitational lensing, caused by the immense galaxy cluster WHL0137-08, acted like a magnifying glass, bringing Earendel into our view.

The most distant star ever detected

But why do we see Earendel as just a solitary point of brilliance? Even the advanced infrared imaging of the Webb shows it as a lone dot. 

Astronomers infer that Earendel is magnified by a staggering factor of 4,000, positioning it as the universe’s most distant star, existing just a billion years post the big bang. This record outshines the previous distant star champion, spotted by Hubble 4 billion years after the universe’s inception.

A possible companion star

Massive stars, like Earendel, often come paired. While it was assumed that any companion of Earendel would be hidden in its brilliance, the colors of the star suggest otherwise. 

Astronomers speculate the presence of a cooler, redder companion, detectable only by Webb, as the universe’s expansion has elongated its light to wavelengths beyond Hubble’s reach.

The Sunrise Arc galaxy

The Sunrise Arc has its own stories. Webb’s NIRCam depicts a vibrant tapestry of young star-forming regions and ancient star clusters, some as tiny as 10 light-years in diameter. 

Like a cosmic mirror, the gravitational lensing effect reflects these celestial features, giving us a peek into the past, possibly resembling how the Milky Way’s globular clusters appeared 13 billion years ago.

Astronomers are eagerly awaiting data from Webb’s NIRSpec, which is expected to provide detailed insights into the composition and distance of both Earendel and the Sunrise Arc galaxy.

More about distant stars

Distant stars are celestial objects that are located many light-years away from Earth. Observing these stars gives us a glimpse into the history of the universe, as the light from distant stars can take billions of years to reach us. 

Studying their properties, such as luminosity, color, and movement, helps scientists understand the nature of stars and galaxies, as well as the overall structure and evolution of the universe. 

Technologies like telescopes and space observatories, including the Hubble Space Telescope, have greatly enhanced our ability to observe and analyze these distant stars.

Every point of light you see in the night sky is a star, many of which are potentially like our Sun, hosting their own family of planets and with their own unique stories to tell.


Stars are classified based on their spectral characteristics, from hottest to coolest: O, B, A, F, G, K, M. Our Sun, for instance, is a G-type star.


The distance to stars is often measured in light-years (ly) or parsecs (pc). One light-year is the distance light travels in one year, which is roughly 9.461 trillion kilometers.


Due to their distance, many stars appear as point sources even in powerful telescopes. To study them, astronomers rely on their emitted light, which can provide insights into their temperature, composition, motion, and more.

Life cycle

All stars go through a life cycle, starting as a molecular cloud and progressing through stages like main sequence, red giant, and depending on their initial mass, may end as a white dwarf, neutron star, or black hole.


Distant stars and galaxies exhibit a phenomenon called redshift, where the emitted light is stretched towards the red end of the spectrum. This phenomenon provides evidence for the expansion of the universe.


Many distant stars have been found to have planets orbiting them. These are called exoplanets. The study of these exoplanets can help scientists understand the potential for life elsewhere in the universe.

Image Credit: NASA, ESA, CSA, and STScI


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