jwst Archives

May 31, 2023May 31, 2023 by Matt Williams

Here's How You Could Get Impossibly Large Galaxies in the Early Universe

The galaxy cluster SMACS0723, with the five galaxies selected for closer study. Credit: NASA, ESA, CSA, STScI / Giménez-Arteaga et al. (2023), Peter Laursen (Cosmic Dawn Center).

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.

May 30, 2023May 30, 2023 by Nancy Atkinson

JWST Spies a Gigantic Water Plume at Enceladus

Images from the NASA/ESA/CSA James Webb Space Telescope’s NIRCam (Near-Infrared Camera) show a water vapour plume jetting from the south pole of Saturn’s moon Enceladus, extending out 40 times the size of the moon itself. The inset, an image from the Cassini orbiter, emphasises how small Enceladus appears in the JWST image compared to the water plume. Credit: NASA, ESA, CSA, STScI, G. Villanueva (NASA’s Goddard Space Flight Center), A. Pagan (STScI).

The James Webb Space Telescope has observed a huge water vapor plume emanating from Saturn’s moon Enceladus. Astronomers say the plume reaches nearly 10,000 kilometers (6,200 miles) into space, which is about the equivalent distance as going from Ireland to Japan. This is the largest plume ever detected at Enceladus.

May 20, 2023May 20, 2023 by Matt Williams

Remember Those Impossibly Massive Galaxies? They May Be Even More Massive

The first image taken by the James Webb Space Telescope, featuring the galaxy cluster SMACS 0723. Credit: NASA, ESA, CSA, and STScI

The James Webb Space Telescope (JWST) was designed to probe the mysteries of the Universe, not the least of which is what the first galaxies looked like. These galaxies formed during the Epoch of Reionization (aka. “Cosmic Dawn”), which lasted from about 100 to 500 million years after the Big Bang. By observing these galaxies and comparing them to ones that see closer to our own today, astronomers hope to test the laws of physics on the grandest of scales and what role (if any) Dark Matter and Dark Energy have played.

Unfortunately, early into its campaign, the JWST detected galaxies from this period so massive that they were inconsistent with our understanding of how the Universe formed. The most widely-accepted theory for how this all fits together is known as the Lambda Cold Dark Matter (LCDM) cosmological model, which best describes the structure and evolution of the Universe. According to the latest results from the Cosmic Dawn Center, these galaxies may be even more massive than previously thought, further challenging our understanding of the cosmos.

May 18, 2023May 18, 2023 by Nancy Atkinson

Astronomers Find an Earth-Sized World That May Be Carpeted in Volcanoes

LP 791-18 d, shown here in an artist's concept, is an Earth-size world about 90 light-years away. The gravitational tug from a more massive planet in the system, shown as a blue disk in the background, may result in internal heating and volcanic eruptions – as much as Jupiter’s moon Io, the most geologically active body in the solar system. Credits: NASA’s Goddard Space Flight Center/Chris Smith (KRBwyle)

Astronomers think they’ve found an extrasolar planet covered in volcanoes like Jupiter’s moon Io, but this world is about the same size as Earth. Designated LP 791-18 d, the planet is probably tidally locked around a small, red dwarf star about 90 light-years away in the constellation Crater. There are two other more massive planets in the system, and their tidal interactions could cause enough tidal flexing that it unleashes planet-wide volcanoes on LP 791-18 d.

Planet d is located within the habitable zone of the star, and with all the other conditions, astronomers think it might be temperate enough on the permanent night side of this world to allow water to exist.

May 17, 2023May 17, 2023 by Evan Gough

JWST Finds a Comet Still Holding Onto Water in the Main Asteroid Belt

This artist's illustration shows the rocky body of a comet with a detailed, cratered surface. Glowing rays emanate from the rocky surface like sunlight through clouds, representing water ice being vapourised by the heat of the Sun. Image Credit: NASA, ESA

Comets are instantly recognizable by their tails of gas and dust. Most comets originate in the far, frozen reaches of our Solar System, and only visit the inner Solar System occasionally. But some are in the Main Asteroid Belt, mixed in with the debris left over after the Solar System formed.

Astronomers just found water vapour coming from one of them.

“With Webb’s observations of Comet Read, we can now demonstrate that water ice from the early Solar System can be preserved in the asteroid belt.”
Michael Kelley, University of Maryland

May 3, 2023May 3, 2023 by Matt Williams

JWST Tries to Untangle the Signals of Water. Is it Coming From the Planet or the Star?

This artist concept represents the rocky exoplanet GJ 486 b. Credits: NASA, ESA, CSA, Joseph Olmsted (STScI)

The number of known extrasolar planets has exploded in the past few decades, with 5,338 confirmed planets in 4,001 systems (and another 9,443 awaiting confirmation). When it comes to “Earth-like” planets (aka. rocky), the most likely place to find them is in orbit around M-type red dwarf stars. These account for between 75 and 80% of all stars in the known Universe, are several times smaller than the Sun and are quite cool and dim by comparison. They are also prone to flare activity and have very tight Habitable Zones (HZs), meaning that planets must orbit very closely to get enough heat and radiation.

In addition, red dwarfs are highly-active when they are young, exposing planets in their HZs to lots of ultraviolet and X-ray radiation. As such, whether planets orbiting these stars can maintain or reestablish their atmospheres over time is an open question. Using the James Webb Space Telescope (JWST), researchers from the Space Telescope Science Institute (STScI) observed an exoplanet known as GJ 486 b. As they stated in a recent study, the team detected traces of water vapor, though it is unclear if the signal was coming from the planet or its parent star.

April 6, 2023April 6, 2023 by Nancy Atkinson

The Rings of Uranus Shine Bright in Stunning New JWST Image

This zoomed-in image of Uranus, captured by Webb’s Near-Infrared Camera (NIRCam) Feb. 6, 2023, reveals stunning views of the planet’s rings. Credit: NASA, ESA, CSA, STScI IMAGE PROCESSING: Joseph DePasquale (STScI).

The James Webb Space Telescope has taken a stunning new image of the ice giant world Uranus. But what stands out most is the dramatic new view of the planet’s rings, which show up as never before with JWST’s infrared eyes.

Instead of being faint and wispy, the rings show up brilliantly. Additionally, bright, luminous features in the planet’s atmosphere show how an extensive storm system at the north pole of this planet getting larger and brighter.

But you’ll also want to see the full-frame image view, which also shows the six largest of Uranus’ 27 known moons. And, as we’ve become accustomed to seeing in JWST images, several distant background galaxies. Yes, every JWST image is a Deep Field!

April 5, 2023April 5, 2023 by Matt Williams

This JWST Image Shows Gravitational Lensing at its Finest

. Credit: ESA/Webb, NASA & CSA, J. Rigby

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.

March 15, 2023March 15, 2023 by Evan Gough

Prelude to a Supernova: The James Webb Captures a Rare Wolf-Rayet Star

The luminous, hot star Wolf-Rayet 124 (WR 124) is prominent at the centre of the NASA/ESA/CSA James Webb Space Telescope’s composite image combining near-infrared and mid-infrared wavelengths of light. Image Credit: NASA, ESA, CSA, STScI, Webb ERO Production Team

Massive stars are sprinters. It might seem counterintuitive that stars 100 or 200 times more massive than our Sun could only survive for as few as 10 million years. Especially since smaller stars like our Sun can last 10 billion years. Massive stars have huge reservoirs of hydrogen to burn through, but their massive size means fusion eats through their hydrogen much more quickly.

These massive stars are destined to reach the finish line quickly and explode as supernovae. There’s no other conclusion for them. But before they explode, some of them become Wolf-Rayet stars. That stage doesn’t last long, and the James Webb Space Telescope caught one in the act.

March 14, 2023March 14, 2023 by Nancy Atkinson

JWST Sees So Many Galaxies, and It's Just Getting Started

The first of COSMOS-Web NIRCam observations obtained on Jan. 5-6, 2023 cover six visits or pointings of the James Webb Space Telescope. This shows the total area observed as well as specific galaxies selected from the first data. Credit: COSMOS-Web/Kartaltepe, Casey, Franco, Larson, et al./RIT/UT Austin/IAP/CANDIDE

Hubble Space Telescope’s Deep Field revealed thousands of galaxies in a seemingly empty spot in the sky. Now, the James Webb Space Telescope has taken deep field observations to the next level with its COSMOS-Web survey, revealing 25,000 galaxies in just six pictures, the first from this new survey.

“It’s incredibly exciting to get the first data from the telescope for COSMOS-Web,” said principal investigator Jeyhan Kartaltepe, from the Rochester Institute of Technology’s School of Physics and Astronomy, in press release. “Everything worked beautifully and the data are even better than we expected. We’ve been working really hard to produce science quality images to use for our analysis and this is just a drop in the bucket of what’s to come.”