Chilling NASA Webb Telescope Image Reveals 'Fingerprint' of Rare Star System
About 5,000 light-years from Earth, 17 dust halos represent over a century of starry congregation.
The two stars in Wolf-Rayet 140 produce shells of dust every eight years that look like rings, as seen in this image from NASA's James Webb Space Telescope.
Since July, NASA's James Webb Space Telescope has delivered some of the most unbelievable space images we've ever laid eyes on. In just a few months, this pioneering machine has built a stunning repertoire of glowing nebular portraits, possible proof of ancient galaxies and even refreshing perspectives of planets in our own solar system.
But on Oct. 12, the JWST shook things up a bit -- again.
As detailed by a paper published in the journal Nature Astronomy, it presented us with an image of 17 concentric dust rings -- though one thing hasn't changed. Like with the rest of the 'scope's lovely space discoveries, these haloes are just as breathtaking as they are crucial to the field of astronomy.
The agency believes these hazy rings are the result of two stars, located just over 5,000 light-years from Earth, treading close enough for their stellar winds to share a kiss now and then. In essence, every time the stars' sparkly streams of gas intertwine, they form a dusty ring. It's almost like they mark their union in spaceborne stone -- or, as NASA puts it, leave behind a "fingerprint."
What's especially fascinating about these stellar memories is they allow us to calculate the passage of time.
Basically, each of those 17 rings signifies exactly one starry rendezvous in the way each ring formed by a tree indicates a year of the plant's life. In fact, the stellar bodies' nested loops even resemble the inside of a tree trunk, bringing about a poignant reminder that everything we see -- from the mightiest stars and farthest planets to the greenest leaves and smallest bugs -- is part of the same, cohesive universe.
Rings inside a tree trunk, like these, indicate the age of the tree.
"We're looking at over a century of dust production from this system," Ryan Lau, an astronomer at the National Science Foundation's NOIRLab and lead author of the new study, said in a statement. "The image also illustrates just how sensitive this telescope is."
Before, with the ground-based telescopes available to us, we were able to see only two dust rings, Lao explains. "Now, we see at least 17 of them."
All in all, from what the JWST captured, scientists think the stars' special meeting occurs about once every eight years.
For the first time, @NASAWebb saw rings of stardust from a rare type of dual star system.
— NASA (@NASA) October 12, 2022
Every eight years, these two stars come close to each other, and the interaction forms a new cosmic ring. Ground scopes saw two; Webb revealed at least 17: https://t.co/7yuUMtPAxa pic.twitter.com/OAz1GhZsWM
The find is thanks to the JWST's Mid-Infrared instrument, of MIRI. In contrast to the 'scope's Near-Infrared sensors -- pretty much the big-dog tool on this machine -- MIRI focuses on light emanating from spaceborne objects found on the mid-infrared region of the electromagnetic spectrum.
Typically, the JWST's Near-Infrared equipment is what gives us the bulk of our beautiful cosmic images, but when it comes to studying outer space dust rings, NASA brings MIRI up to bat. This part of the JWST is simply better suited to find cooler objects, the agency says, like the wispy hoops, and even succeed in revealing their composition.
Further, the study team notes, one star in this stellar system is considered a rarity.
It's called a Wolf-Rayet star. (The duo is aptly named Wolf-Rayet 140 because of this). The other star is an O-type star, a superhot object that's also relatively difficult to spot.
Wolf-Rayet stars, unlike standard stars, shed an incredible amount of mass over time, meaning they also tend to spit out heavy elements rooted deeply inside them. They also have a lot of mass to shed because they're at least 25 times more massive than our sun. And at the end of their life, they tend to turn into some of the most extreme known objects in our universe: black holes.
This graphic shows the relative size of the sun, upper left, compared with the two stars in the system known as Wolf-Rayet 140. The O-type star is roughly 30 times the mass of the sun, while its companion is about 10 times the mass of the sun.
According to NASA, stars generally eject only the (very light) element hydrogen. But it's those heavy elements emitted by Wolf-Rayets that cool in the stellar wind, thereby compressing when they meet another star's breeze and potentially fostering the right environment for new stars to form. In fact, some scientists believe the sun rose from compressed Wolf-Rayet residue long ago.
With regard to WR-140, such compression seems to form the concentric circles we see left behind. Possibly, the agency explains, that's because of the system's elongated orbit. Only about 600 of these so-called Wolf-Rayet stars have been found in our galaxy so far, though scientists suspect there should be at least a few thousand total.
"Even though Wolf-Rayet stars are rare in our galaxy because they are short lived as far as stars go, it's possible they've been producing lots of dust throughout the history of the galaxy before they explode and/or form black holes," Patrick Morris, an astrophysicist at Caltech and co-author of the new study, said in a statement.
"I think with NASA's new space telescope we're going to learn a lot more about how these stars shape the material between stars and trigger new star formation in galaxies."