Most Distant 'Star' Might Actually Be a Star Cluster

The astronomical object Earendel, which is regarded as the most distant star ever observed, may not be a single star at all. 

A new study led by researchers at the University of California suggests that Earendel’s light is more consistent with a dense cluster of stars rather than an individual one. 

According to lead author Massimo Pascale, the spectroscopic data match what astronomers expect from star clusters formed around 30 to 150 million years after the Big Bang.

Earendel was first detected more than three years ago by the Hubble Space Telescope. 

What makes the observation extraordinary is that we are seeing the object less than a billion years after the universe’s birth. 

This glimpse into the early cosmos was only possible because a massive cluster of galaxies in the foreground acted as a gravitational lens, bending and magnifying Earendel’s light on its way to Earth.

Initially, astronomers believed Earendel to be a massive B-type star—roughly twice as hot as our Sun and over a million times brighter. 

This assumption inspired Pascale and his colleagues to test whether the object could instead be an entire collection of stars.

While the new analysis strengthens the case for Earendel being a star cluster, the scientific debate remains unresolved. 

One of the astronomers involved in its original discovery noted that Pascale’s team did not fully explore all possible explanations for the data. Both sides agree, however, that only further observations—particularly with the James Webb Space Telescope—can provide a definitive answer.

The findings have been published in The Astrophysical Journal Letters.