Hubble pushed to its horizon: a star 900 million years after the Big Bang
Hubble is pushing its limits to new horizons.
Scientists released data from the Hubble Space Telescope on a star or star system roughly 900 million years after the Big Bang — the cataclysmic beginnings of the universe, according to a Wednesday study published in the journal Nature.
This object is far more distant than earlier observations of similar systems — which means we're looking at one of the earliest stages ever witnessed by humans of our universe. And in addition to its unwieldy size, the mystery object is incredibly distant.
It's so distant, in fact, that only the James Webb Space Telescope could top Hubble's incredible findings.
Hubble spots an extremely old star with gravitational lensing
The unspeakably distant object was nicknamed "Earendel," which means "morning star" or "rising light" in Old English. To view it, astronomers used gravitational lensing — a feature of the universe where the light of distant objects is magnified by the gravity of closer ones. Scientists estimate Earendel's mass to be more than 50 times that of the sun, with a redshift of 6.2, according to an embargoed press release shared with IE.
And the unconscionably distant object is either a star or a double star system. "It's by far the most distant individual star that we've ever seen," said Jane Rigby of NASA, a co-author of the new paper, in a report from National Geographic. "This will be our best chance to study what an individual massive star was like in the early universe."
Redshift reflects how light "stretches" as it moves through the universe, but also serves as a cosmic timestamp — and thus a marker of distance — of astronomical objects. The larger the value of redshift, the farther away it is, which, in turn, implies a greater distance from us, the observers.
Earlier observations of stars seen via gravitational lensing have been made in the past, at redshifts from 1 to 1.5. We don't know the temperature, mass, or spectral properties of the star, but this information might be revealed once the James Webb Space Telescope begins its science missions.
Hubble's single-star discovery was no easy feat
To observe this cosmic object, astronomers aimed Hubble at a gigantic cluster of galaxies called WHL0137-08. These galaxy clusters are so big that the collective force of gravity actually warps the fabric of space-time around it, bending light — and, if correctly aligned with us on Earth, it allows us to see background objects at extremely high magnification.
And this observation is also a first of its kind — in the past, Hubble has spotted galaxies merely 300 or 400 million years after the Big Bang. But these are sources of light from countless stars united in one or more galaxies. "For those, we're seeing the light from millions of stars all blended together," said Brian Welch, lead study author and doctoral student at Johns Hopkins University, according to an AP report. "In this one, it's magnified so that we can see just this one star."
The star or star system in the new study is singular, or binary — marking the earliest star (or stars) seen this far back in time. Locking down a view of a singular star is no easy feat. But hold on to your seats: In the coming months, we might have a visual of this ancient system. Once the James Webb Space Telescope — which could see back 13.7 billion years — begins its proper scientific missions, it could see stars just like this one, from the dawn of the early universe.
This was developing news about Hubble's discovery of an extremely distant star from the early universe and was regularly updated as new information became available.