August 15, 2023

On the left, the galaxy cluster WHL0137-08 and in the inset, the galaxy nicknamed the Sunrise Arc in its distorted form, which hosts the star Earendel

Two articles, one published in “The Astrophysical Journal” and one in “The Astrophysical Journal Letters”, report various aspects of a study of Earendel, the most distant single known star. Two teams of researchers with several members in common used observations conducted with the James Webb Space Telescope to obtain new details of this star, which even such a powerful instrument could only detect thanks to a gravitational lens. Officially cataloged as WHL0137-LS, the new study turns out to be a class B blue giant, much more massive than the Sun. Webb’s observations also reveal a luminous component that could belong to a less massive companion and not even the Hubble Space Telescope was able to detect.