The James Webb Space Telescope has revealed the secrets of Earendel, the farthest star ever discovered in the universe, lying at the edge of time. Earendel is so far away that its light has taken 13 billion years to reach us through a cosmic coincidence of line of sight. But this doesn't mean that it's 13 billion light-years away. The proper distance of this star, which also considers the universe's expansion, is about 28 billion light years. Also, if the Big Bang theory is correct, this means that we are actually looking at a star that existed within the first billion years of the universe. Hence, it could belong to the elusive first generation of stars that astronomers have been hunting for decades.
But Earendel is so far away that it's impossible to study its properties in detail with Earth-based telescopes or even the Hubble Space Telescope. And this is where the James Webb Space Telescope comes into the picture.
So, how did astronomers discover Earendel, a lone star so far away in the cosmos? How is it different from the stars we observe in the local universe? Finally, and most importantly, why were astronomers surprised by the James Webb Space Telescope observations of Earendel?
The 72nd episode of the Sunday Discovery Series answers all these questions in detail.
