Astronomers have discovered the first “galaxy bubble” in our galaxy’s backyard, an almost impossibly large cosmic structure believed to be a fossilized remnant from just after the Big Bang. The bubble spans a billion light-years, making it 10,000 times larger than the Milky Way galaxy.

However, this giant bubble, which cannot be seen with the naked eye, is located 820 million light years away from our galaxy, in what astronomers call the near universe. This bubble can be seen as a “spherical shell with a heart,” according to astrophysicist Daniel Pomarede of the French Atomic Energy Commission.

Within this heart lies the Volopas supercluster of galaxies, surrounded by a vast void sometimes referred to as the “Great Void.” The crust contains several other galaxy superclusters already known to science, including a massive structure known as Sloan’s Great Wall.

Pomarede said the discovery of the balloon was described in a study he co-authored and published in the journal. Astrophysical Journal this week “was part of a very long scientific process.”

This confirms the phenomenon first described in 1970 by American cosmologist and future Nobel laureate in physics Jim Peebles. He theorized that in the early universe, which was then composed of hot plasma, the decay of gravity and radiation created sound waves called baryon acoustic oscillations (BAOs).

When sound waves penetrated the plasma, it formed bubbles.

This process stopped about 380,000 years after the Big Bang when the universe cooled and the bubbles froze in shape. Like other fossilized remains of the time after the Big Bang, the bubbles grew larger as the universe expanded. Astronomers had previously detected BAO signals in 2005 by looking at data from nearby galaxies. However, according to the researchers, the newly discovered bubble is the first known single baryonic acoustic oscillation.

“Unexpected”

Astronomers named their bubble Ho’oleilana (“sending the noise of awakening”), after a Hawaiian creation song. It is named after lead study author Brent Tully, an astronomer at the University of Hawaii. The bubble was discovered by chance as part of Tully’s work to find new galaxy catalogues.

“It was unexpected,” Pomarede said.

Tully said in a statement that the bubble was “so large that it extended to the edges of the sky sector we analyzed.” The pair enlisted the help of Australian cosmologist and BAO expert Callan Howlett, who “mathematically determined the global structure that best fit the data,” Pomarede said. This allowed the trio to visualize the three-dimensional shape of Ho’oleilana and the location of the galactic archipelago within it. This may be the first, but more bubbles will soon be detected in the universe.

The European Euclidean Space Telescope, launched in July, provides a wide view of the universe, potentially allowing it to capture a few more bubbles. Massive radio telescopes called the Square Kilometer Array, which are being built in South Africa and Australia, could also provide a new picture of galaxies from a Southern Hemisphere perspective, Pomarede said. Source