NASA’s Hubble Space Telescope has spotted the most distant single star ever detected in outer space. The star—dubbed Earendel from an Anglo-Saxon word meaning rising light or morning star—lies 12.9 billion light-years from Earth and formed about 900 million years after the Big Bang. Earendel is 8.2 billion years older than the Earth and Sun and 12.1 billion years older than when the first animals appeared on the planet, reports Rafi Letzter for the Verge. Earendel was described in a paper published this week in Nature. The study shines light on the youngest stars gleaming in the cosmos.
“When the light that we see from Earendel was emitted, the universe was less than a billion years old,” says study author Victoria Strait, an astronomer at the Cosmic Dawn Center in Denmark, in a statement. “At that time, it was 4 billion light-years away from the proto-Milky Way, but during the almost 13 billion years it took the light to reach us, the universe has expanded so that it is now a staggering 28 billion light-years away.”
Astronomers suspect that Earendel is even older than Icarus, the previous record-holder detected by Hubble in 2018. Icarus appeared in outer space 9.5 billion years ago, reports Jake Parks for Astronomy.
Officially known as WHL0137-LS, Earendel was detected by chance when a galaxy cluster aligned with the ancient star and was magnified through a phenomenon called gravitational lensing, a statement explains. Gravitational lensing can magnify distant objects when their light bends and travels along the gravitational curvature of the massive object like a galaxy or galaxy cluster, reports Michelle Starr for Science Alert.
As the light from the distant object bends, the far-away object appears distorted or smudged, but it is also duplicated and magnified. After detecting the light, astronomers can pinpoint where the magnified object is. When seeing objects from early in the universe, or cosmic dawn, the smears of detected light are usually galaxies, per Science Alert. The Hubble telescope detected Earendel after homing in on a magnified streak of light boosted by a nearby galaxy.
Within the galaxy, study author Brian Welch, an astrophysicist at Johns Hopkins University, found the primordial star sitting at the top of the lensing critical curve, or where the magnification is most intense, Science Alert reports. Before reaching the Hubble, the star near the critical point was magnified between 1,000 and 40,000 times. The galaxy was dubbed the Sunrise Arc because of the gravitational lensing effect that made it appear as a long crescent shape, the Verge reports.
Comment: This is just one more example of a concept that is clearly beyond my grasp. Laying on the ground on a dark, clear night to gaze at the full Moon and maybe pick out the various constellations is my kind of astronomy. This talk of gravitational lensing just boggles my mind. And that image above from the Smithsonian article, with the squiggly magnification line, could be an April Fools’s Day joke for all I know. I doff my cap to these high end astronomers. The other articles linked to this “Smithsonian” article shed some more light on these concepts. I hesitate to tackle the more technical “Nature” article, but why not? FIDO.