Astronomers identified a vast, bubble-like structure known as Hoʻoleilana in the distribution of relatively nearby galaxies, estimated at 1 billion light-years in diameter and described as the first observation of an individual Baryon Acoustic Oscillation (BAO).

The cosmic bubble is located around 820 million light-years from Earth and is a staggering one billion light-years wide. It sits within a web of galaxies and has been given the name “Ho’oleilana,“ which is a term from the Hawaiian creation chant Kumulipo. Ho’oleilana describes the origin of structure and relates to the stars and the moon. Massive structures such as Ho’oleilana are predicted to arise in the universe as a result of tiny ripples in the hot, dense and mostly uniform sea of matter which existed at the beginning of time. These density ripples, called BAOs, grew as the universe underwent a period of rapid inflation (called the Big Bang).

The ripples are also known to have given rise to major cosmic structures while influencing the distribution of galaxies. However, this is the first identification of a single structure associated with a BAO. The bubble itself is composed of previously identified structures that themselves have been considered some of the universe’s largest arrangements of matter. This includes several superclusters, or groups of galaxy clusters, that each contain 10 clusters and span up to 200 million light-years. At the heart of Ho’oleilana lies the Bootes supercluster and the Bootes void, which is a 330 million-light-year-wide space of nothingness. The bubble was found using datasets collected by Cosmicflows-4, which were published in 2022 and marks the largest compilation of precise distances to galaxies.

Vast bubble of galaxies discovered, given Hawaiian name

Bubble of galaxies spanning 1 billion light-years could be a fossil of the Big Bang