NameHawaiian for "immense heaven"proposed by Nawa'a Napoleon[1]
Held together?nonot dense enough; it will disperse[4]
Part of a larger basin?possiblyabout 60% odds in a 2024 study, centred on Shapley[6]
About the image. Drawn as streams of galaxies flowing along curving paths into one bright region, with the Milky Way as a small spiral near the edge. The flows follow the 2014 maps of galaxy motions; the colours, the glow of the streams and the look of individual galaxies are imagined. Laniakea's edge is a divide between flows, not a visible wall.
Laniakea is the supercluster we live in. It holds about 100 000 galaxies, including the Milky Way, and spans about 160 megaparsecs, roughly 500 million light-years. Its mass is about a hundred million billion Suns. Unlike a planet or a galaxy, it has no visible edge. It was drawn in 2014 from the way galaxies move.
A watershed of galaxies
Galaxies do not only drift apart as the universe expands. Each is also pulled towards the denser regions around it. In 2014 Tully, Courtois, Hoffman and Pomarède measured these extra motions for more than 8 000 galaxies and traced where each one is heading. Inside one region, all the flows point inward towards a shared low point, like rain running down into a single river basin. That region is Laniakea. Its boundary is the line where flows part, like a ridge between two valleys, with galaxies on the far side heading somewhere else. The Milky Way sits in its outskirts.
The low point the flows lead to is near the Great Attractor, in the direction of the constellation Norma. The two are often confused: Laniakea is the whole basin, and the Great Attractor is roughly where its streams meet. A 2026 study by Stiskalek and colleagues goes further and argues that the classical Great Attractor is “an artefact of the instantaneous velocity field”, and that where the flows seem to converge depends on how finely they are mapped.
Immense heaven
The name was suggested by Nawa’a Napoleon, a Hawaiian-language professor at Kapiolani Community College. In Hawaiian it means “immense heaven”, and it honours the Polynesian navigators.
Not forever, and maybe not alone
Laniakea is a pattern of today’s motions, not a permanent object. In 2015 Chon, Böhringer and Zaroubi showed that it is not dense enough to hold together: over time its galaxies will scatter.
It may not even be a separate basin. In 2024 Valade and colleagues repeated the analysis with the much larger Cosmicflows-4 catalogue, about 38 000 groups of galaxies, and found a slight preference for Laniakea being part of a far larger basin centred on the Shapley concentration. The University of Hawaiʻi put the odds at about 60%, for a basin up to ten times its volume. “At the moment it’s just a hint,” said co-author Libeskind.
Gallery
Fine golden and white streamlines of countless tiny galaxies sweeping in from the lower left and gathering in a bright golden region like a feather, an impression of the galaxy flows of the Laniakea Supercluster. AI-generated painting.A small bright galaxy seen edge-on at the lower left, in a faint stream of stars leading towards a large golden glow of crowded galaxies, an impression of the Milky Way in the outskirts of Laniakea. AI-generated painting.Laniakea Supercluster, 3D artist's impression, rendered from the interactive model.Laniakea Supercluster, 3D artist's impression, from another angle, rendered from the interactive model.Laniakea Supercluster, 3D artist's impression, close-up, rendered from the interactive model.
Timeline
2014Tully, Courtois, Hoffman and Pomarède define Laniakea from the motions of over 8 000 galaxies.
2015Chon and colleagues show it is not dense enough to hold together.
2023Dupuy and Courtois map Laniakea and five more basins with Cosmicflows-4.
2024Valade and colleagues find a slight preference for Laniakea being part of the larger Shapley basin.
2026A new study calls the classical Great Attractor an artefact of the velocity field.
Questions people ask
What is the Laniakea Supercluster?
The region of space in which about 100 000 galaxies, including the Milky Way, all flow towards a common gravitational basin. It was defined in 2014 from the motions of over 8 000 galaxies.
How big is Laniakea?
About 160 megaparsecs across, roughly 500 million light-years, with the mass of about a hundred million billion Suns.
Is Laniakea part of something bigger?
Possibly. A 2024 study found a slight preference, about 60% odds, for Laniakea being part of a basin up to ten times larger, centred on the Shapley concentration.