Space and astronomy news
When the James Webb Space Telescope was launched at the end of 2021, we expected stunning images and illuminating scientific results. So far, the powerful space telescope has lived up to our expectations. The JWST has shown us things about the early Universe we never anticipated.
Some of those results are forcing a rewrite of astronomy textbooks.
Continue reading “The JWST is Re-Writing Astronomy Textbooks”
One of the main objectives of the James Webb Space Telescope (JWST) is to study the early Universe by using its powerful infrared optics to spot the first galaxies while they were still forming. Using Webb data, a team led by the Cosmic Dawn Center in Denmark pinpointed three galaxies that appear to have been actively forming just 400 to 600 million years after the Big Bang. This places them within the Era of Reionization, when the Universe was permeated by opaque clouds of neutral hydrogen that were slowly heated and ionized by the first stars and galaxies.
This process caused the Universe to become transparent roughly 1 billion years after the Big Bang and (therefore) visible to astronomers today. When the team consulted the data obtained by Webb, they observed that these galaxies were surrounded by an unusual amount of dense gas composed almost entirely of hydrogen and helium, which likely became fuel for further galactic growth. These findings already reveal valuable information about the formation of early galaxies and show how Webb is exceeding its mission objectives.
Continue reading “Galaxies in the Early Universe Preferred their Food Cold”
One of the chief objectives of the James Webb Space Telescope (JWST) is to study the formation and evolution of the earliest galaxies in the Universe, which emerged more than 13 billion years ago. To this end, scientists must identify galaxies from different cosmological epochs to explore how their properties have changed over time. This, in turn, requires precise dating techniques so astronomers are able to determine when (in the history of the Universe) an observed galaxy existed. The key is to measure the object’s redshift, which indicates how long its light has been traveling through space.
This is the purpose of the Cosmic Evolution Early Release Science Survey (CEERS), a collaborative research group that analyzes Webb data to learn more about galactic evolution. These galaxies are known as “high-redshift,” meaning that their light emissions are redshifted all the way into the infrared spectrum. Galaxies that existed ca. 13 billion years ago can only be observed in the near-infrared spectrum, which is now possible thanks to Webb’s Near-Infrared Camera (NIRCam). Even so, obtaining accurate redshift measurements from such distant galaxies is a very tricky, and requires advanced techniques.
Continue reading “Why Was it Tricky to Know the Distances to Galaxies JWST Was Seeing?”
After years of build-up and anticipation, the James Webb Space Telescope finally launched into orbit on December 25th, 2021 (what a Christmas present, huh?). Since then, the stunning images and data it has returned have proven beyond a doubt that it was the best Christmas present ever! After its first year of operations, the JWST has lived up to one of its primary objectives: to observe the first stars and galaxies that populated the Universe. The next-generation observatory has accomplished that by setting new distance records and revealing galaxies that existed less than 1 billion years after the Big Bang!
These studies are essential to charting the evolution of the cosmos and resolving issues with our cosmological models, like the Hubble Tension and the mysteries of Dark Matter and Dark Energy. Well, hang onto your hats because things have reached a new level of awesome! In a recent study, an international team of scientists isolated a well-magnified star candidate in a galaxy that appears as it was almost 12.5 billion years ago. The detection of a star that existed when the Universe was only ~1.2 billion years old showcases the abilities of the JWST and offers a preview of what’s to come!
Continue reading “JWST Plucks One Single Star out of a Galaxy Seen 12.5 Billion Years Ago”
One of the main objectives of the James Webb Space Telescope (JWST) is to use its powerful optics and advanced instruments to observe the earliest galaxies in the Universe. These galaxies formed about 1 billion years after the Big Bang, coinciding with the end of what is known as the “Cosmic Dark Ages.” This epoch is inaccessible for conventional optical telescopes because the only sources of photons were largely associated with the relic radiation of the Big Bang – visible today as the Cosmic Microwave Background (CMB) – or were the result of the reionization of neutral hydrogen (visible today the 21 cm line).
Thanks to its advanced optics and infrared imaging capabilities, Webb has pushed the boundaries of how far astronomers and cosmologists can see. One of the most interesting finds was Maisie’s galaxy, which appeared to have existed roughly 390 million years after the Big Bang. According to a new study by the Cosmic Evolution Early Release Science Survey (CEERS) that recently appeared in Nature, these results have since been confirmed. This makes Maisie’s galaxy one of the farthest (and earliest) confirmed galaxies ever observed by human eyes.
Continue reading “You’re Looking at One of the Farthest Confirmed Galaxies Found by JWST”
One of the most interesting (and confounding) discoveries made by the James Webb Space Telescope (JWST) is the existence of “impossibly large galaxies.” As noted in a previous article, these galaxies existed during the “Cosmic Dawn,” the period that coincided with the end of the “Cosmic Dark Age” (roughly 1 billion years after the Big Bang). This period is believed to hold the answers to many cosmological mysteries, not the least of which is what the earliest galaxies in the Universe looked like. But after Webb obtained images of these primordial galaxies, astronomers noticed something perplexing.
The galaxies were much larger than what the most widely accepted cosmological model predicts! Since then, astronomers and astrophysicists have been racking their brains to explain how these galaxies could have formed. Recently, a team of astrophysicists from The Hebrew University of Jerusalem Jerusalem published a theoretical model that addresses the mystery of these massive galaxies. According to their findings, the prevalence of special conditions in these galaxies (at the time) allowed highly-efficient rates of star formation without interference from other stars.
Continue reading “Here's How You Could Get Impossibly Large Galaxies in the Early Universe”
One of the James Webb Space Telescope’s science goals is to help cosmologists understand how the first galaxies and galaxy clusters formed in the early Universe. New images from the telescope show just that. Astronomers say the seven galaxies shown in this new JWST images are the earliest yet to be spectroscopically confirmed as part of a developing galaxy cluster. These galaxies are about 13 billion light-years away, meaning JWST is seeing them at about 95% of the age of the observable Universe.
Continue reading “JWST Sees a Galaxy Cluster Coming Together in the Early Universe”
One of the more intriguing aspects of the cosmos, which the James Webb Space Telescope (JWST) has allowed astronomers to explore, is the phenomenon known as gravitational lenses. As Einstein’s Theory of General Relativity describes, the curvature of spacetime is altered by the presence of massive objects and their gravity. This effect leads to objects in space (like galaxies or galaxy clusters) altering the path light travels from more distant objects (and amplifying it as well). By taking advantage of this with a technique known as Gravitational Lensing, astronomers can study distant objects in greater detail.
Consider the image above, the ESA’s picture of the month acquired by the James Webb Space Telescope (JWST). The image shows a vast gravitational lens caused by SDSS J1226+2149, a galaxy cluster located roughly 6.3 billion light-years from Earth in the constellation Coma Berenices. The lens these galaxies created greatly amplified light from the more distant Cosmic Seahorse galaxy. Combined with Webb‘s incredible sensitivity, this technique allowed astronomers to study the Cosmic Seahorse in the hopes of learning more about star formation in early galaxies.
Continue reading “This JWST Image Shows Gravitational Lensing at its Finest”
In the first data taken last summer with the Near Infrared Camera (NIRCam) on the new James Webb Space Telescope, astronomers found six galaxies from a time when the Universe was only 3% of its current age, just 500-700 million years after the Big Bang. While its incredible JWST saw these galaxies from so long ago, the data also pose a mystery.
These galaxies should be mere infants, but instead they resemble galaxies of today, containing 100 times more stellar mass than astronomers were expecting to see so soon after the beginning of the Universe. If confirmed, this finding calls into question the current thinking of galaxy formation and challenges most models of cosmology.
Continue reading ““The Universe Breakers”: Six Galaxies That are Too Big, Too Early”
Staring off into the ancient past with a $10 billion space telescope, hoping to find extraordinarily faint signals from the earliest galaxies, might seem like a forlorn task. But it’s only forlorn if we don’t find any. Now that the James Webb Space Telescope has found those signals, the exercise has moved from forlorn to hopeful.
But only if astronomers can confirm the signals.
Continue reading “Astronomers Pin Down the Age of the Most Distant Galaxy: Seen 367 Million Years After the Big Bang”