Record-Breaking View: Webb Uses Physics Trick to Spot 44 Distant Stars in a Galaxy Far, Far Away

The Webb Space Telescope captured a record-breaking representation of stars successful the Dragon Arc, a serpentine crescent of a postulation successful the distant universe.

The postulation is simply a whopping 6.5 cardinal light-years from Earth and Webb’s caller snapshot of it captures 44 idiosyncratic stars, seen acknowledgment to the telescope’s singular capabilities and the fortuitous layout of objects betwixt the scope and the galaxy. Let america explain.

The Dragon Arc is conscionable that—a bent portion of airy successful space—because its airy is flattened by the gravity of intervening objects. Those intervening objects are gravitational lenses, which crook and refocus the airy from much distant objects, magnifying them to an perceiver (in this case, the Webb Space Telescope).

Lens wrong a lens

In a caller study, a radical of astronomers scrutinized Webb observations of a postulation clump and well-known gravitational lens known arsenic Abell 370. The clump magnified the distant stars by astir 100 times, and a prima wrong the clump acted arsenic a lens wrong that lens, making the distant stars travel into sharper relief. The team’s probe describing the people stars was published this week successful Nature Astronomy.

An illustration showing however Webb collects information connected highly distant stars. Graphic: Yoshinobu Fudamoto

“Inside the postulation cluster, determination are galore stars floating astir that are not bound by immoderate galaxy,” said Eiichi Egami, a probe prof astatine Steward Observatory and co-author of the paper, successful an Arizona State University release. “When 1 of them happens to walk successful beforehand of the inheritance prima successful the distant postulation on the enactment of show with Earth, it acts arsenic a microlens, successful summation to the microlensing effect of the postulation clump arsenic a whole.”

New possibilities

The lensception, if you will, made it imaginable for the probe squad to prime retired idiosyncratic stars which different would person been excessively fuzzy to marque out. The squad studied the stars and concluded that “many of them are accordant with reddish giants oregon supergiants magnified by factors of hundreds,” arsenic the radical wrote successful the paper.

“This groundbreaking find demonstrates, for the archetypal time, that studying ample numbers of idiosyncratic stars successful a distant postulation is possible,” said Fengwu Sun, a researcher astatine the Center for Astrophysics | Harvard & Smithsonian, successful the release.

Such reddish stars are nearing the end of their lives. As the stars usage up their fuel, they swell and offload reams of state and dust. Webb is nary alien to specified past stars; successful 2022 and 2023, the state-of-the-art observatory trained its oculus connected Earendel, the astir distant known star, and found signs that the past shot of state whitethorn person a spouse successful crime.

Discovering a azygous distant prima is singular connected its own. In November 2024, astronomers captured the first elaborate image of a prima extracurricular our galaxy—a reddish supergiant successful its last stages of life. But a full postulation of stars is much scientifically useful. As the squad wrote, the enactment demonstrates that “observations by the Webb Space Telescope could pb to the anticipation of conducting statistical studies of high-redshift stars.”

Astronomers volition behaviour follow-up observations of the arc with the Webb telescope, which are expected to uncover much of the magnified stars wrong the distorted galaxy. Besides helping scientists recognize however antithetic gravitational lenses magnify past light, the findings could uncover aspects of dark matter.