Many hoped that the James Webb Space Telescope might finally shed light on some of the universe’s longest-standing mysteries even before it was launched. It was hailed as a powerful time machine that could see back 13.5 billion years to see the earliest stars and galaxies form from the void of the early cosmos.
Less than three months after the telescope’s full scientific operations began, it is already beginning to live up to its highest hopes.
Webb has been utilized by researchers from Canada’s NIRISS Unbiased Cluster Survey (CANUCS) to find the most remote star clusters ever seen. These so-called “globular clusters” may contain some of the oldest and most ancient stars in the universe.
The first deep field image taken by JWST allowed the research team to focus on the “Sparkler Galaxy,” which is located 9 billion light-years away. This galaxy got its name from the glittering appearance of the yellow-red flecks in the backdrop.
Younger clusters of actively-forming stars born during the peak of star formation in the universe (about three billion years after the Big Bang) or much older globular clusters — ancient collections of stars from a galaxy’s infancy, containing clues about its formation and growth — had been argued to be responsible for these sparkles.
Researchers have determined that five of the first analysed 12 compact objects from Webb’s high-resolution picture are, in fact, globular clusters; and not just any clusters, but one of the oldest ones we have known!
Even though our Milky Way galaxy contains over 150 globular clusters, scientists still don’t know nearly enough about their formation. All we know is that they can be really old, but until the Webb Telescope came along, we had no way of knowing for sure.
Hubble telescope studies of the Sparkler Galaxy have previously been unable to reveal the presence of nearby compact objects. In order to be seen, the JWST’s enhanced resolution and sensitivity had to be paired with the natural magnification provided by the gravitational lensing effect, which was produced by the SMACS 0723 galaxy cluster in the foreground.
Next month, when the James Webb telescope will focus on the CANUCS galaxy clusters, the study team is expecting to find additional similar discoveries as a result of the enhanced equipment and assisting phenomena. This research will use models of the clusters to decipher the lensing effect, and they will also carry out rigorous analysis to expand on the history of star formation.
Meanwhile, yesterday’s issue of The Astrophysical Journal Letters featured this study’s results.