The JWST images
Introduction
On the 12th of July, 2022, NASA, in collaboration with the ESA, publicly released the first few images from the James Webb Space Telescope (JWST).
This telescope is a hallmark and testimony to the profound impacts advancements on technology can have on scientific research and development.
A collection of 5 images (Excluding spectra graphics and counting the MIRI image of the Southern Ring Nebula as a separate image) were released publicly, these images focused on various different celestial objects ranging from galaxies to nebulae.
To those without any knowledge in astronomy, these images are purely mesmerising for the beauty the telescope has managed to capture. However, for the average astronomer, these images are a window into the remarkable scope (pun intended) of the telescope.
This article will attempt to highlight what exactly each image shows, and the significance of this image.
Stephan’s Quintet
The first image we will be looking at is the image of Stephan’s Quintet
Just for good measure, here is an image comparing the image taken by Webb’s predecessor: The Hubble Space Telescope
The image on the left is from JWST while the image on the right is from Hubble. The difference in clarity is indisputable.
Stephan’s Quintet was discovered in 1877 by French Astronomer Édouard Stephan.
The Quintet highlights five galaxies (NGC 7317, NGC 7318A, NGC 7318B, NGC 7320) together. However,
NGC 7320 is actually an astounding 250 million light years away from the other four galaxies. Hence, this galaxy is way too far to be “affected” by the other four. As a result, the other four galaxies form a separate celestial grouping called HCG 92 (Hickson Compact Group)
The quintet allows us to understand galaxy mergers and evolution a lot deeper than before. For example, scientists can look at the extent to which merging galaxies can cause star formation. Furthermore, each galaxy is home to a supermassive black hole, some up to the order of ten million times the mass of the sun. Using a special method of analysis called Near Infrared Spectrograph (NIRSpec) and Mid Infrared Instrument (MIRI), astronomers were able to see even tiny individual stars within the image.
The Carina Nebula
The image below shows us the mesmerising Carina Nebula
The Carina Nebula is a 300 light year wide nebula that is approximately 7600 light years away from us. Like all nebulae, it is a stellar nursery, giving rise to young stars. As the JWST primarily works with infra-red light, we are able to see stars that we wouldn’t have otherwise been able to see.
The JWST decided to focus on a specific part of the nebula called “The Cosmic Cliffs” (NGC 3324).
The Cosmic Cliffs were formed as a result of high Ultraviolet (UV) radiation and stellar winds (High velocity particles emitted from a star) caused by really young stars at a high temperature.
This specific area allows us to truly study the initial stages of the stellar lifecycle, more specifically the stage of star formation.
The Southern Ring Nebula
Below shows the Southern Ring Nebula as taken by NIRCam (Near Infrared Camera) and MIRI respectively
The difference between NIRCam and MIRI is that NIRCam mainly focuses on the stars in the nebula while MIRI photographs the stellar dust in the localised region.
To first understand this image, it is recommended to have a working knowledge of the stellar lifecycle.
Check out my article on the same topic:
The Southern Ring Nebula is a planetary nebula, as a result this allows us to study what are essentially dying stars. This nebula is a molass of gas, dust, and other “space stuff”. It was caused by the expulsion of material from a dying white dwarf star.
Analysis of the nebula enables astronomers to collect more data on the gas, dust, as well as their composition and varying properties.
What’s also interesting is that as these stars continue to give out more material, this material can clump together due to gravity to form other stars or planets as well.
In the above image, you might notice how the photo from NIRCam shows one star twinkling in what is approximately the centre of the nebula while the photo from MIRI shows two dots. This is because one of the stars is actually cloaked by dust. The brighter star is also a younger star.
The two stars above form a binary star system (Two stars that are gravitationally bound to each other and that orbit around a common point)
The Deep Field
I was saving my favourite image for the last: The Deep Field image. I feel that this image truly highlights the power of the JWST.
Once again, here is a comparison between The Deep Field taken by JWST and the one taken by the Hubble
Deep field observations are essentially photos taken by looking at a particular part in the sky for a really long time and collecting light from that specific area.
Each individual dot in the above image is an individual galaxy.
The phenomena known as gravitational lensing is even more clear in the image by the JWST. If you concentrate hard on the centre of the photo, you will notice that it looks slightly distorted and curved. This is known as gravitational lensing and occurs when gravitational pulls distort light emitted by far away galaxies.
In fact, the galaxies responsible for the gravitational lensing in the image are part of a galactic cluster (a group of galaxies that are bound together by gravity).
The Deep Field image will allow astronomers to look at galactic evolution with pretty a much a fine-tooth comb as ages and masses of stars within galaxies can be measured more accurately. This will help us not only ascertain a better galactic evolution model but will also help us understand how a young universe has affected its evolution cycle.
With that, I will be ending this article. As always, I hope you enjoyed.
