It’s been more than three months since astronomers waited with bated breath, endured an hour of the undeniable earworm that is the NASA hold music, and feasted their collective eyes upon the first image from JWST. While the public’s JWST experience began there, the road to the first JWST images began years earlier for the scientists and administrators working behind the scenes. Let’s take a quick look at the creation of those first images — an immense effort that culminated in 26,000 news articles viewed 120 billion times.
In 2017, representatives from NASA, the Canadian Space Agency, the European Space Agency, and the Space Telescope Science Institute began the process of selecting JWST’s first targets. How do you select five targets from an entire universe of possibilities? You ask a bunch of astronomers, of course! The selection committee polled members of the American Astronomical Society to get a broad list of targets, which the JWST Early Release Observations committee narrowed down to just 70 that reflected JWST’s four main science themes — stars and galaxies in the early universe, galaxy formation, stellar evolution, and planetary systems near and far. The five-member Early Release Observations Core Implementation Team, led by Klaus Pontoppidan (Space Telescope Science Institute), made the final target decisions.
After the data for the first images were collected in June and July 2022, the image visualization team faced a daunting task: combining data taken at many different wavelengths into images that are both informative and beautiful. With few exceptions, the team opted to follow chromatic ordering, assigning redder colors to longer wavelengths and bluer colors to shorter wavelengths, while selecting filters that highlight the physical characteristics of the target. For example, in the images of the Carina Nebula shown above, the filters were selected to trace ionized gas, jets and outflows, dust, and polycyclic aromatic hydrocarbons — organic molecules containing carbon atoms arranged in rings.
Though the iconic images from JWST have long since captured our imaginations (and taken over our desktop backgrounds), the image processing work continues. Check out the full article linked below for more details on how the first JWST images were created — and be sure to take a look at the full gallery of JWST images released so far!
Citation
“The JWST Early Release Observations,” Klaus M. Pontoppidan et al 2022 ApJL 936 L14. doi:10.3847/2041-8213/ac8a4e