Monday Astronomy Picture Ponderings 4/25/2022
Welcome back to the Monday Astronomy Picture Ponderings (MAPPs) series where every Monday I normally pick one of NASA’s Astronomy Picture of the Day (APOD) entries from the past seven days to focus on in some way. This week, since I’m traveling, I’m taking the opportunity to focus on an exciting image that’s been in the news recently.
This week’s MAPPs feature is dedicated to the amazing picture by the Hubble Space Telescope of the furthest observed stable star, WHL0137-LS, nicknamed Earendel. I had researched it before my trip and planned to publish this on 4/13, but life decided to throw me a few curveballs.
NASA Astronomy Picture of the Day featured Earendel on April 6th, 8 days after Hubble spied the fascinating star lying nearly 13 billion light-years away.
Hubble broke its previous record-holding star in 2018 (9 billion light-years away) thanks to a lucky happenstance. Earendel was around when the universe was only about 4 billion years old. Despite the fact that Earendel is at least 50 times the mass of our Sun and millions of times as bright, we shouldn’t have been able to detect it.
“Normally at these distances, entire galaxies look like small smudges, with the light from millions of stars blending together,” said [astronomer Brian] Welch [of the Johns Hopkins University in Baltimore, lead author of the paper describing the discovery]. “The galaxy hosting this star has been magnified and distorted by gravitational lensing into a long crescent that we named the Sunrise Arc.” — Record Broken: Hubble Spots Farthest Star Ever Seen
A galaxy cluster, WHL0137–08, between us and Earendel is so massive that it warped space-time, creating gravitational lensing, a natural magnification and brightening technique, similar to ripples in a pool of water. This “caustic”, or ripple, magnified Earendel by at least a thousandfold, brightening the far-distant star.
While Hubble’s capture of this star is ground-breaking, we are looking forward to future study of this star by other instruments, including the new James Webb Space Telescope, which was specifically designed for looking back in time at far distant objects of this nature.