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 the Big Bang.
Because 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.
The first billion years of the Universe’s history following the Big Bang 13.8 billion years ago, also known as the Cosmic Dawn, are very difficult to see. Not only is it murky and dark very early, when the first stars and galaxies form, it’s also extremely distant. Even finding quasars, the brightest objects in the Universe, stretches the capabilities of our technology and analysis techniques.
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. [Continue reading…]