After months of waiting, NASA’s James Webb Space Telescope has finally debuted some new images of the cosmos. This time, they’re full-color and spectroscopic.
These images were captured by Webb’s NIRCam, which sees the universe in the near and mid-infrared. These wavelengths are invisible to the human eye, but they reveal information about the chemical composition of astronomical objects.
1. SMACS 0723
The James Webb Space Telescope, the successor to the Hubble Space Telescope, has revealed an incredible image of the early universe, overflowing with thousands of galaxies. Captured with the telescope’s Near-Infrared Camera (NIRCam), this incredible image, known as “Webb’s First Deep Field,” reveals the clearest picture of the universe to date.
The cluster of galaxies in the center of this infrared photo is called SMACS 0723 and it can be seen near the constellation Volans in the Southern Hemisphere. It’s one of the first targets for a number of scientific investigations carried out on the telescope during its commissioning phase, and a key example of the type of observations that the JWST is designed to do.
SMACS 0723 is a huge galaxy cluster that acts as a gravitational lens, bending light from more distant galaxies behind it towards the telescope. This cosmic magnification effect is an important way to look at distant galaxies and enables us to see the details of their shapes.
In this image, we see that SMACS 0723 is surrounded by a multitude of red dots and strangely-shaped galaxies. These objects are among the oldest in the universe, and some are even as old as 13 billion years.
What’s more, this image is the deepest and sharpest infrared photo of the distant universe ever captured. It contains thousands of galaxies, including some of the faintest and smallest objects ever observed in this wavelength range.
The JWST was launched last December to pursue two primary goals — taking pictures of the very first stars that shined in the universe, and probing far-off planets. This stunning snapshot shows that the $10bn telescope is up to the task.
The telescope also has an instrument called NIRSpec, which uses a microshutter array to capture the spectra of individual galaxies in the very early part of the history of the universe. This is a major breakthrough, as it enables researchers to see spectra of individual galaxies from the very first stages of their evolution. These spectra can tell scientists whether the stars that make up those galaxies are made from hydrogen, oxygen or another element.
2. Stephan’s Quintet
Stephan’s Quintet is a collection of five galaxies that are in a dance of near-collisions. This group, which is also known as Hickson Compact Group 92, provides an excellent laboratory for studying galaxy collisions and their impact on the surrounding environment.
Using Webb’s infrared capabilities, astronomers uncovered never-before-seen details of the group in images released on July 12. The image, which spans about one-fifth of the Moon’s diameter, is made up of over 150 million pixels and is based on 1,000 separate image files.
The image of the Stephan’s Quintet reveals hundreds of thousands of open clusters of stars, a tail of gas and dust that is being drawn from the galaxies and huge shock waves produced by NGC 7318B as it collides with the other four members. In addition, it also shows how the other galaxies are triggering star formation within themselves as well as how their hot gases are being disturbed.
It’s an amazing example of what happens when space gets too crowded, a phenomenon referred to as cosmological singularity. The group of galaxies is 290 million light-years from Earth and lies in the constellation Pegasus.
As with the Carina Nebula and the Southern Ring Nebula, the Stephan’s Quintet reveals the effect of massive star death on gas in the vicinity of a supermassive black hole. In this case, the black hole is pulling in heated gas, causing it to shine at an enormously bright level in the infrared wavelengths that Webb sees.
According to NASA, the resulting image gives scientists a glimpse of how interactions like these can drive galaxy evolution in the early universe. These interactions can spawn stars in a way that is very different from what we see in the Milky Way galaxy, which is not so affected by these kinds of collisions.
The James Webb telescope, which launched in April, has already captured a number of impressive images that are helping scientists understand the nature of our Milky Way galaxy. The first of these, a portrait of the galaxy group Stephan’s Quintet, was taken by JWST’s Wide Field Camera 3 (WFC3) on a service mission in May 2009.
3. Southern Ring Nebula
When the James Webb telescope was launched in July of this year, a portrait of the Southern Ring Nebula was among the first images it released to the public. Located in the constellation Vela, this nebula is well known to southern-hemisphere astronomers because it can be seen high in the sky during winter months.
The Southern Ring Nebula (also known as NGC 3132) is one of the most beautiful and mysterious nebulae in the sky. It has a striking oval shape and features intricate filaments that extend outward from the nebula’s center, giving it its ring-like appearance.
Originally, the Southern Ring Nebula was thought to be just an ordinary planetary nebula – a shell of gas and dust that was ejected from a dying star. But a team of astronomers now suspect that at least two nearby stars played an important role in its creation.
That’s because those companions interacted with the red star that created the nebula, causing it to shed its outer layers and triggering its nebula formation process. The two interacting stars also caused jets of dust to be thrown outward. The jets produced what JWST officials called “opposing bumps” in the nebula’s dusty cloud, which now form the asymmetrical shells in the nebula’s interior.
These asymmetrical shells are surrounded by very hot gas, which is a product of the intense light from the dying star. And the nebula’s outermost edge is covered in cold dust and molecules that formed at the time of nebula formation, about 1,000 years ago.
Now, Webb has cast the nebula in new light by observing it in mid-infrared wavelengths, which allow the telescope to see much more of the nebula’s details than its infrared image could. By analyzing this data, Webb’s images reveal the dusty star at the center of the nebula in more detail than any other previously available picture.
Webb’s imaging also shows the stars that helped shape the Southern Ring Nebula, showing them to be a pair – and they’re not far apart from the red star that created the nebula. The pair sprang up in the same place around 2,500 years ago, and were accompanied by a third star as they shredded their outer layers.
4. Milky Way
The Milky Way is the most recognizable galaxy in the universe. As a result of decades of astronomical research, scientists have been able to make an accurate assessment of its size and shape.
The Milky Way has a disk about 120,000 light-years across with a central bulge that has a diameter of 12,000 light years. This is warped in shape, a feature that we attribute to its two neighbors – the Large and Small Magellanic clouds.
There are a large number of stars, many of which are clusters and associations that are made up of tens to thousands of individual stars. These stars are different in size and in age.
Typically, they are yellowish or orange in color and appear to be packed tightly together, with bright stars forming the center of the group and dimmer stars forming the outer edges.
It is estimated that there are between 100 billion and 400 billion stars in the Milky Way, though it is impossible to know exactly how many there are.
Astronomers have recently mapped the structure of our galactic home using a technique called a Dark Energy Camera. This is a powerful instrument that allows astronomers to peer into the obscuring dust in the plane of the Milky Way and capture images of stars, star clusters, and even black holes in their vicinity.
A team of astronomers used this tool to create the world’s first image of a black hole at the heart of our galaxy. This black hole, known as Sagittarius A*, is located at the centre of our galaxy and is so huge that no light can escape its event horizon.
Previously, astronomers had only used visible wavelengths to map stars and clusters within the Milky Way’s disk. This method was flawed, however, because the vast amounts of dust in the Milky Way absorb light and make it appear dimmer than it really is.
So, astronomers had to come up with a new technique to accurately map the stars and star clusters in the Milky Way. The Dark Energy Camera is an infrared-based instrument that can see through the opacity of the Milky Way’s dust and can map stars, star clusters, and black holes in their vicinity.