Introducing a New Milestone: Webb Telescope Discovers 44 Stars Close to the Big Bang's Aftermath
Astronomers utilizing the James Webb Space Telescope have utilized a space distortion to spot over 40 individual stars in a far-off galaxy, nestled 6.5 billion light-years away from our Milky Way — essentially halfway back to the universe's inception. This discovery boasts the largest number of individual stars ever detected in the distant universe.
The incredible image, yielding benefits from JWST's remarkable optics, was only feasible due to the light from 44 distant stars being magnified by a colossal cluster of galaxies, called Abell 370, situated in front of it.
Gravitational Lensing
This groundbreaking technique, known as gravitational lensing — or an "Einstein ring" due to its affiliation with the renowned physicist Albert Einstein's predictions — works when a galactic cluster's potent gravitational field warps the space around it. Light then bends away from an object behind it, creating circular rings or arcs. These formations serve to not only reveal the existence of something in the background but also magnify it by up to a thousand times. In this instance, an arc appeared, christened the "Dragon Arc."
The study's findings were published today in a Nature Astronomy paper authored by scientists hailing from the Center for Astrophysics, Harvard & Smithsonian in Cambridge, Massachusetts. The press release accompanying the paper compared the achievement to attempting to discern individual specks of dust inside the moon's craters using binoculars.
Pioneering Discovery
"This groundbreaking discovery demonstrates for the first time that analyzing large collections of individual stars in a distant galaxy is possible," said postdoctoral researcher Fengwu Sun, one of the paper's co-authors. Previous Hubble Space Telescope investigations identified around seven stars. With JWST's prowess, resolving stars previously considered beyond our reach has now become feasible.
Scientists are far from expecting to find individual stars in galaxies halfway across the universe. Nevertheless, this record-breaking achievement serves a more significant function than just being a milestone. They hope it will also contribute towards improved understanding of dark matter.
Dark matter — the name given to hypothetical, undetectable particles presumed to make up around 85% of the universe's mass — interacts with gravity yet absorbs, reflects, and emits no light or energy. Observing more individual stars helps researchers gain a better grasp on the dark matter present in the lensing plane of these galaxies and stars, which was previously elusive with just a few individual stars under observation.
Red Supergiant Stars
Many stars present in the Dragon Arc are red supergiants, similar to Betelgeuse in Orion and Aldebaran in Taurus, both currently visible in the eastern night sky shortly after sunset. JWST's sensitivity to infrared light made their detection possible.
"We know more about red supergiants in our local galactic neighborhood due to their proximity," said Sun. "However, we can draw on the knowledge gained from studying these red supergiants in our own galaxy to unravel what occurs next for them at such an early epoch of galaxy formation in future studies."
The team anticipates that JWST's historic discovery will be followed up by additional observances focusing on magnified stars in the Dragon Arc galaxy and other distant galaxies.
Mayer you gaze upon starlit skies with both wonder and understanding.
The James Webb Space Telescope's image of the distant galaxy, magnified by the gravitational lensing effect of Abell 370, allowed astronomers to spot 44 individual stars, including many red supergiants like Betelgeuse and Aldebaran. This discovery, published in a Nature Astronomy paper, marks the largest number of individual stars identified in a distant galaxy, potentially shedding light on the existence and behavior of dark matter.
