The HydraâÂÂCentaurus Supercluster (SCl 128), or the Hydra and Centaurus Superclusters, was a previously defined supercluster in two parts, which prior to the identification of Laniakea Supercluster in 2014 is the closest neighbour of the former Virgo Supercluster. Its center is located about away, with it extending to a maximum distance of around .
The supercluster includes four large galaxy clusters in the Centaurus part, also known as the "4 clusters<nowiki></nowiki> filament, or <nowiki></nowiki>4 clusters strand<nowiki></nowiki>:
The filament which also includes the major cluster Abell S753 and exends up to around to reach the rich galaxy cluster Abell 3581.
The Antlia Wall, also known as the Antlia Strand, Hydra Wall, Hydra-Antlia wall, Hydra-Antlia extension, and the Hydra-Antlia filament, is a filament that emerges from the Centaurus Cluster, passes under the Zone of Avoidance (ZOA) as the "Puppis filament", to link up the Lepus Cloud. This filament then passes through a region containing the NGC 1600 Group before crossing the boundary where the gravitional flows of galaxies between the Laniakea and PerseusâÂÂPisces superclusters diverge to link up with the PerseusâÂÂPisces supercluster at a distance of around from the Centaurus Cluster. The filament contains two major clusters:
In 2014, it was revealed that the Antlia Wall along with the rest of the HydraâÂÂCentaurus supercluster is connected to the PerseusâÂÂPisces Supercluster. Later in 2017, Pomarède et.al identified based on the flow of galaxies that the Antlia Wall along with the Lepus Cloud are part of a substantial filament known as the CentaurusâÂÂPuppisâÂÂPP Filament that extends around from the Centaurus Cluster all the way to the PerseusâÂÂPisces supercluster. The CentaurusâÂÂPuppisâÂÂPP Filament along with the Southern Supercluster Strand which contains the Eridanus-Fornax-Dorado Filament and the TelescopiumâÂÂGrus Cloud, are part of wall that makes up the front boundary of the Sculptor Void.
Before 2017, it was not known that the Antlia Wall and the Lepus Cloud were part of the same structure, the CentaurusâÂÂPuppisâÂÂPP Filament. This is because the CentaurusâÂÂPuppisâÂÂPP Filament goes under the ZOA of the Milky Way, which caused parts of the filament to be obscured by the disk of the galaxy on the sky, resulting in the naming of the different visible pieces of filament.
Apart from the central clusters, which are 150 to 200 million light years away, several smaller clusters belong to the group.
Within the proximity of this supercluster lies the Great Attractor, dominated by the Norma Cluster (Abell 3627). This massive cluster of galaxies exerts a large gravitational force, causing all matter within 50 Mpc to experience a bulk flow of 600 km/s toward the Norma Cluster.
A 2014 announcement says that the Centaurus Supercluster (HydraâÂÂCentaurus) is just a lobe in a greater supercluster, Laniakea, that is centered on the Great Attractor. That supercluster would include the Virgo Supercluster, therefore including the Milky Way where Earth resides.