Scientists simply introduced that they’ve detected what is likely to be a number of the earliest galaxies to kind within the universe, a tantalizing discovery made because of NASA’s new flagship James Webb Space Telescope. 

“This is the first large sample of candidate galaxies beyond the reach of the Hubble Space Telescope,” astronomer Haojing Yan mentioned yesterday at a press convention on the American Astronomical Society assembly in Seattle. Yan, who’s on the University of Missouri, led the newly published study. Because the extra delicate JWST can see additional into deep area than its predecessor Hubble does, it basically sees additional again in time. In the brand new catalog of 87 galaxies astronomers have noticed utilizing it, some might date again to about 13.6 billion years in the past, simply 200 million years after the Big Bang. That’s when the galaxies emitted the sunshine that we’re seeing right this moment—though these programs of stars, fuel, and mud would have modified dramatically since then, in the event that they nonetheless exist in any respect.

While scientists have studied other faraway galaxies that date again to when the universe was nonetheless younger, the discoveries by Yan and his colleagues might break these data by a number of hundred million years or so. But at this level, they’re all nonetheless thought of “candidate galaxies,” which implies that their birthdates nonetheless want affirmation. 

Dating a galaxy generally is a difficult matter: It entails measuring its “redshift,” how a lot the sunshine it emits is stretched towards longer purple wavelengths, which tells astronomers how briskly the galaxy is transferring away from us within the shortly increasing universe. That, in flip, tells astronomers the galaxy’s distance from Earth—or extra precisely, the space that the photons from its stars needed to journey on the velocity of sunshine earlier than reaching an area telescope close to the Earth, like JWST. Light from stars in essentially the most distant galaxy on this assortment might have been emitted 13.6 billion years in the past, doubtless pretty quickly after the younger galaxy got here collectively. 

These newly estimated distances must be confirmed with spectra, which implies measuring the sunshine the galaxies emit throughout the electromagnetic spectrum and pinpointing its distinctive signatures. Still, Yan expects a lot of them to be accurately dated to the early days of the cosmos: “I’ll bet $20 and a tall beer that the success rate will be higher than 50 percent,” he mentioned.

Yan’s group imaged these galaxies with JWST’s NIRCam at six near-infrared wavelengths. To estimate their distances, the astronomers used a regular “dropout” method: Hydrogen fuel surrounding galaxies absorbs mild at a specific wavelength, so the wavelengths at which an object can or can’t be seen places a restrict on how distant it’s prone to be. These 87 candidate galaxies principally appear like blobs that may solely be detected within the longer (and subsequently redder) near-infrared wavelengths detectable by NIRCam, which might imply they’re very distant, and subsequently very previous. 

However, it’s doable that a few of them may very well be a lot nearer than anticipated—which might imply they aren’t so previous in any case. For instance, it may very well be that their mild is simply too faint to be detected at some wavelengths. Until Yan can gather extra detailed information, he received’t know for positive.