29/01/2026
Webb paljastaa outoja varhaisia galakseja
James Webb Space Telescope on löytänyt pienen joukon erittäin erikoisia galakseja varhaisesta maailmankaikkeudesta. Ne ovat pieniä ja tiiviitä, m***a eivät sovi tuttuihin galaksiluokkiin – eivät tähtiä, eivät kvasaarigalakseja.
Havaittu valo on peräisin jopa 12–12,6 miljardin vuoden takaa. Kohteet saattavat edustaa galaksien muodostumisen hyvin varhaista vaihetta, jota emme ole aiemmin nähneet.
Meet our current record holder for farthest galaxy ever seen (so far!!)
MoM-z14 may look like an unimpressive little yellow smudge here, but it's our first view of a galaxy that existed just 280 million years after the big bang and lies over 13.5 billion light years away from here. It took our most powerful space telescope, the infrared James Webb Space Telescope, to see it. Webb is doing what it was built to do, look for the first stars and galaxies that formed in the early universe during “Cosmic Dawn.” Cosmic Dawn is defined as an era from around 50 million to 1 billion years after the big bang, when the first luminous objects appeared. Because of the expansion of the universe, the light from these extremely distant objects is also shifted as it travels through expanding spacetime. Visible light becomes redder. Webb, with its huge mirror, gold-coated to optimize it for reflecting infrared light, was designed to be able to see the light from these first bright objects that formed in the universe’s infancy.
MoM-z14 will help teach us about the universe’s historical timeline and is also showing just how different the early universe was from what astronomers expected it to be. For example, high amounts of nitrogen are detectable in early galaxies like MoM-z14 (and also found in the oldest stars in our own galaxy) but such early galaxies shouldn’t have had the time to produce such high amounts of nitrogen - at least not in ways astronomers would expect. One theory is that the dense environment of the early universe resulted in supermassive stars capable of producing more nitrogen than any stars observed in the local universe.
MoM-z14 also shows signs of clearing out the thick, primordial hydrogen fog of the early universe in the space around itself. Scientists are looking to learn more about the timeline of this period of cosmic history, when early stars produced light of high enough energy to break through the dense hydrogen gas of the early universe and begin travelling through space, eventually making its way to Webb, and us.
Read more:
https://go.nasa.gov/4kfIUMj
Image credit: NASA, ESA, CSA, STScI, Rohan Naidu (MIT); Image Processing: Joseph DePasquale (STScI)
