Even before launch, there were high hopes for the James Webb Space Telescope, as it was expected to solve some of the universe’s long-standing mysteries. It was described as a powerful time machine capable of looking 13.5 billion years into the past and observing the first stars and galaxies to emerge from the darkness of the early universe.
Now, nearly three months since the telescope began full-scale scientific operations, it is beginning to deliver on all of its greatest promises.
With Webb’s help, researchers from Canada’s NIRISS Unbiased Cluster Survey (CANUCS) recently identified the most distant groups of stars ever found. In fact, these ‘globular clusters’ may even contain some of the earliest and oldest stars in the Universe!
Using the first deep-field image taken by JWST, the research team was able to zoom in on the “Sparkler Galaxy,” located nine billion light-years away. The galaxy gets its name from the surrounding yellow-red dots, which actually look like sparkles.
These sparks have been claimed to represent one of two phenomena: either 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 childhood, containing clues about its formation and growth.
After first analyzing 12 such compact objects from Webb’s finely detailed image, the researchers were able to determine that five of them are indeed globular clusters – and not just any clusters, but one of the oldest known!
“Because we were able to observe the glare over a range of wavelengths, we were able to model them and better understand their physical properties, such as how old they are and how many stars they contain. We hope that the knowledge that globular clusters from such great distances can be observed with JWST, will stimulate further science and searches for similar objects,” said Kartheik G. Iyer, a fellow at the Dunlap Institute for Astronomy & Astrophysics at the University of Toronto and co-lead author of the study.
Although our Milky Way Galaxy is home to about 150 globular clusters, we still don’t know enough about how and when these dense clusters of stars formed. All we know is that they may be extremely old, but measuring their age was not possible until the advent of the Webb telescope.
Lamiya Mowla, another Dunlap colleague and co-researcher, added: “These newly identified clusters formed close to the first time it was even possible to form stars. Because the Sparkler galaxy is much further away than our own Milky Way, it’s easier to determine the ages of its globular clusters. We observe the Sparkler as it was nine billion years ago, when the universe was only four and a half billion years old.”
Previous observations of the Sparkler Galaxy, made using the Hubble telescope, had failed to show the compact objects around it. They only became visible when the increased resolution and sensitivity of the JWST were combined with the natural magnification provided by the gravitational lensing effect created by the SMACS 0723 galaxy cluster in their foreground.
Thanks to this improved technology and supporting phenomena, the research team hopes to make more such discoveries next month, when the James Webb telescope will turn its attention to the CANUCS galaxy clusters. These studies will model the clusters to understand the lensing effect, while also performing robust analyzes to deepen the history of star formation.
Meanwhile, the findings of this study were published yesterday in The astrophysical journal lettersand be accessible here.
Download for weather, science and COVID-19 updates on the go The Weather Channel app (in Android and iOS store). It is free!