The James Webb Space Telescope has recently provided a mesmerizing snapshot of NGC 6822, commonly referred to as Bernard’s galaxy. This remarkable image not only grants us a detailed view of a galaxy merely 1.5 light years distant but also offers potential insights into the appearance and dynamics of the nascent universe.
Located proximally to the Milky Way, Bernard’s galaxy stands out due to its low metallicity, encompassing mostly hydrogen and helium with very few other elements. Such characteristics are indicative of the universe’s primitive stages, before the inaugural stars experienced their cycles of birth, life, and demise. As the European Space Agency (ESA) pointed out, the myriad elements beyond hydrogen and helium mainly originate from stars over their lifespan.
Galaxies like NGC 6822, which display reduced metallicities, serve as invaluable windows into the past. They allow astronomers to theorize and study events like star birth and the evolution of cosmic dust in a young universe.
To capture the intricate details of this galaxy, the Webb telescope employed its Near-InfraRed Camera (NIRCam) and Mid-InfraRed Instrument (MIRI). These tools, adept at delving into various portions of the electromagnetic spectrum, facilitate a comprehensive examination of distinct facets of a single galaxy. While the NIRCam focuses on the densely clustered stars, MIRI is attuned to regions rich in gas.
The combined observations from these instruments have unveiled the splendors of Bernard’s galaxy like never before. The NIRCam imagery has transformed the galaxy’s gas and dust into delicate red strands, laying bare countless stars in unmatched precision. In contrast, the MIRI’s perspective focuses on the galactic dust, obscuring the stars and highlighting the luminescent blue emitted by essential organic chemicals known as polycyclic aromatic hydrocarbons. These compounds play a pivotal role in the genesis of stars and planets.
This extraordinary revelation by the James Webb Space Telescope heralds a new chapter in our cosmic exploration, enabling scientists to delve deeper into the mysteries of the universe’s early days.