From billions of light-years across the vast gulf of space-time, from the very dawn of the Universe, astronomers have detected the light of a single star.
Its discoverers have nicknamed it Earendel, from the Anglo-Saxon word meaning"morning star"; to date, it is the most distant object of its kind ever detected, dating to just 900 million years after theBecause Earendel's light has traveled so far to reach us, its properties are difficult to discern, but follow-up observations have already been approved for the James Webb Space Telescope.
But there's a quirk of gravity that can show us small, distant things that might otherwise be beyond our reach. It's called gravitational lensing, and it has to do with the gravitational curvature of space-time around massive objects, such as galaxies and galaxy clusters. The home galaxy of Earendel, whose real name is the rather less pretty WHL0137-LS, was first picked up by the Hubble Space Telescope as just such a smear, magnified by a massive galaxy cluster. There, within the galaxy, a team led by astrophysicist Brian Welch of Johns Hopkins University found a single bright object sitting right on top of the lensing critical curve.
An analysis of the UV light from Earendel suggested the object is around 50 times the mass of the Sun. But more detail than that is too difficult to tease out from the available data. We don't know the spectral classification of the star, for instance, which would be useful.that have survived billions of years, but more massive stars tend to die younger, so knowing what type of star it is would elucidate the Universe's early evolution just a smidge.