Astronomers unearth gigantic 'bubble of galaxies' spanning one billion light-years

An international team of astronomers has unveiled the existence of the very first “bubble of galaxies.” This colossal cosmic structure stretches an astonishing one billion light-years in diameter, offering an unprecedented glimpse into the universe’s early days, just after the Big Bang.

According to the research findings released this week, this celestial behemoth dwarfs even our Milky Way galaxy by a staggering factor of 10,000.

“This phenomenal bubble is a relic from the cosmic dawn, dating back 13 billion years to the birth of our universe,” explained Cullan Howlett, a member of the team hailing from The University of Queensland’s School of Mathematics and Physics. He added, “We weren’t actively seeking it, but this structure is so vast that it sprawled across the very edges of the sky sector we were scrutinizing.”

Remarkably, this newly unveiled cosmic bubble encompasses renowned cosmic structures like the Sloan Great Wall and the Bootes supercluster, adding to its mystique. Even more astonishing, it resides right in our cosmic neighborhood, centered approximately 820 million light-years away from our Milky Way in what astronomers term the nearby universe.

The implications of this monumental discovery extend far beyond its awe-inspiring dimensions. Howlett believes that this revelation provides a profound insight into the universe’s expansion rate, suggesting that it may have expanded more than initially theorized. In his words, “We’re now on the cusp of a paradigm shift in cosmology, where the entire model of the universe may require a reassessment.”

‘The Great Nothing’

Adding to the intrigue, Daniel Pomarede, another team member and an astrophysicist at France’s Atomic Energy Commission, described the bubble of galaxies as “a spherical shell with a heart.” Within this heart lies the Bootes supercluster, surrounded by an expansive void often dubbed “the Great Nothing.” The shell also encompasses numerous galaxy superclusters already known to science, notably the colossal Sloan Great Wall.

Pomarede emphasized that this revelation is the culmination of an extensive scientific process. The discovery also validates a theory first postulated by Canadian-American cosmologist Jim Peebles in 1970. Peebles theorized that in the early universe, characterized by a seething cauldron of hot plasma, the interplay of gravity and radiation generated sound waves known as baryon acoustic oscillations (BAOs).

These sound waves propagated through the plasma, giving rise to the formation of bubbles. Roughly 380,000 years following the Big Bang, as the universe cooled, these bubbles solidified in shape. Subsequently, as the universe expanded, these primordial bubbles enlarged, analogous to other fossilized relics from the post-Big Bang era.

While astronomers had previously detected BAO signals in 2005 while examining data from nearby galaxies, this newly uncovered bubble represents the first-known single baryon acoustic oscillation, a revelation of extraordinary significance.

In a nod to its profound significance and the spirit of cosmic exploration, the astronomers christened their discovery “Ho’oleilana,” which translates to “sent murmurs of awakening” from a Hawaiian creation chant. The name was bestowed by the study’s lead author, Brent Tully, an astronomer affiliated with the University of Hawaii.