Meet Earendel, the most distant star ever detected

NASA/ESA, B. Welch, D. Coe

The most distant star, or possibly a pair of stars, that has ever been seen, was just revealed thanks to the Hubble telescope and a massive cluster of galaxies. The universe bends around the vast bulk of a galaxy cluster, creating a curved lens in spacetime similar to a magnifying glass. It revealed a hidden star system from the early universe.

The astronomer who found the star system called it Earendel, which means "morning star" in Old English.

The authors of a new paper in the journal Nature say that the earendel system was discovered just 900 million years after the Big bang. The light that reached the Hubble Space Telescope was magnified by a lucky trick of gravity to appear as a small smudge on the sensor. Earendel is more than 12 billion years older than the first animals on the planet.

The previous record holder, nicknamed "Icarus", appeared more recently than Earendel, but it still stands out. The oldest known supernovas are younger than Earendel.

NASA, ESA, and P. Kelly (University of Minnesota)

Seeing through a lens.

Earendel's home galaxy, the Sunrise arcs, is named after the effect that made this discovery possible.

A massive cluster of galaxies in the foreground has magnified and stretched this galaxy into a long, thin crescent shape, according to the lead author of the Nature paper.

He stumbled across Earendel while he was studying the lens.

magnifying glasses tend to warp and twist images and have areas of higher and lower magnification. If you have a magnifying glass at home, the best magnification is at the center of the circle. It's difficult to use giltational lenses.

The critical curve is where the magnification is the most intense. The objects seen through the lens appear multiple times. The more they line up with the line of the curve from our perspective, the bigger they get.

The goal of the model was to measure the magnification of the Sunrise Arc.

The bright point was so close to the critical curve that Hubble's sharp eye resolved its doubled, reflected image across the line as a single smudge. The proximity to the critical curve meant that whatever it was, it had already been magnified thousands of times before reaching Hubble. It appeared to Hubble as small and faint, but it was much smaller than the scale of the Sunrise Arc galaxy.

The source was too small to be anything other than a single star.

The ancient universe.

A large international team of coauthors spent three and a half years studying Earendel across multiple Hubble observations to confirm that they were seeing something real and not a fleeting effect of the light.

These old stars can teach us things about the history of the universe, and that time and effort was worth it.

We can see into the past and into a time when the universe looked very different than it does today.

Heavy elements like carbon, oxygen, and even iron can be formed when lighter atoms like hydrogen and helium are fused together through nuclear fusion. Earendel probably had very little material heavier than helium in its system.

Studying this lensed star in detail gives us a new glimpse into what stars were like in the early days of the universe.

The James Webb Space Telescope is currently being used for science operations. The authors wrote in the paper that Earendel is a single star system and not a cluster of star systems lumped together. They hope to learn more about Earendel's temperature and mass, as well as other properties.

Astronomers have been anticipating the launch of the JWST for a long time, and will be busy making its way through a scientific wish list that has grown over the years. Earandel, a star system that glowed at the dawn of time, will be studied as well as exoplanets and the ancient universe.