The Laniakea Supercluster (; Hawaiian for "open skies" or "immense heaven") is the

galaxy A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...

supercluster A supercluster is a large group of smaller galaxy clusters or galaxy groups; they are among the largest known structures in the universe. The Milky Way is part of the Local Group galaxy group (which contains more than 54 galaxies), which in turn ...

that is home to the

Milky Way The Milky Way is the galaxy that includes our Solar System, with the name describing the galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars that cannot be individually distinguished by the naked eye ...

and approximately 100,000 other nearby galaxies. It was defined in September 2014, when a group of astronomers including R. Brent Tully of the

University of Hawaiʻi The University of Hawaiʻi System, formally the University of Hawaiʻi and popularly known as UH, is a public college and university system that confers associate, bachelor's, master's, and doctoral degrees through three universities, seven com ...

, Hélène Courtois of the

University of Lyon The University of Lyon (french: Université de Lyon), located in Lyon and Saint-Étienne, France, is a center for higher education and research comprising 11 members and 24 associated institutions. The three main universities in this center are: ...

, Yehuda Hoffman of the

Hebrew University of Jerusalem The Hebrew University of Jerusalem (HUJI; he, הַאוּנִיבֶרְסִיטָה הַעִבְרִית בִּירוּשָׁלַיִם) is a public research university based in Jerusalem, Israel. Co-founded by Albert Einstein and Dr. Chaim Weiz ...

, and

Daniel Pomarède Daniel Pomarède (born October 3, 1971) is a staff scientist at the Institute of Research into the Fundamental Laws of the Universe, CEA Paris-Saclay University. He co-discovered Laniakea, a home supercluster of galaxies. Specialized in data ...

of CEA

Université Paris-Saclay Paris-Saclay University (french: Université Paris-Saclay) is a public research university based in Paris, France. It is one of the 13 prestigious universities that emerged from the division of the University of Paris, also known as the Sorbonne. ...

published a new way of defining superclusters according to the relative velocities of galaxies. The new definition of the local supercluster subsumes the prior defined local supercluster, the

Virgo Supercluster The Virgo Supercluster (Virgo SC) or the Local Supercluster (LSC or LS) is a mass concentration of galaxies containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least ...

, as an appendage. Follow-up studies suggest that the Laniakea Supercluster is not gravitationally bound; it will disperse rather than continue to maintain itself as an overdensity relative to surrounding areas.

Name

The name () means 'immense heaven' in Hawaiian, . The name was suggested by Nawaʻa Napoleon, an associate professor of Hawaiian language at Kapiolani Community College. The name honors

Polynesian navigators Polynesian is the adjectival form of Polynesia. It may refer to: * Polynesians, an ethnic group * Polynesian culture, the culture of the indigenous peoples of Polynesia * Polynesian mythology, the oral traditions of the people of Polynesia * Poly ...

, who used knowledge of the heavens to navigate the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

Characteristics

The Laniakea Supercluster encompasses approximately 100,000 galaxies stretched out over . It has the approximate mass of 10¹⁷ solar masses, or 100,000 times that of our galaxy, which is almost the same as that of the

Horologium Supercluster The Horologium-Reticulum Supercluster, is a massive supercluster spanning around 550 million light-years. It has a mass of around 1017 solar masses, similar to that of the Laniakea Supercluster The Laniakea Supercluster (; Hawaiian for " ...

. It consists of four subparts, which were known previously as separate superclusters: *

, the part in which the Milky Way resides. *

Hydra–Centaurus Supercluster The Hydra-Centaurus Supercluster (SCl 128), or the Hydra and Centaurus Superclusters, is a supercluster in two parts, the closest neighbour of Virgo Supercluster. Hydra-Centaurus The cluster includes four large galaxy clusters in the Centaurus p ...

** the

Great Attractor The Great Attractor is a gravitational anomaly in intergalactic space and the apparent central gravitational point of the Laniakea Supercluster. The observed anomalies suggest a localized concentration of mass millions of times more massive than ...

, Laniakea's central gravitational point near

Norma Norma may refer to: * Norma (given name), a given name (including a list of people with the name) Astronomy *Norma (constellation) * 555 Norma, a minor asteroid *Cygnus Arm or Norma Arm, a spiral arm in the Milky Way galaxy Geography *Norma, Lazi ...

Antlia Wall Antlia (; from Ancient Greek ''ἀντλία'') is a constellation in the Southern Celestial Hemisphere. Its name means "pump" in Latin and Greek; it represents an air pump. Originally Antlia Pneumatica, the constellation was established by Nic ...

, known as

Hydra Supercluster Hydra generally refers to: * Lernaean Hydra, a many-headed serpent in Greek mythology * ''Hydra'' (genus), a genus of simple freshwater animals belonging to the phylum Cnidaria Hydra or The Hydra may also refer to: Astronomy * Hydra (conste ...

Centaurus Supercluster Centaurus is a bright constellation in the southern sky. One of the 88 modern constellations by area, largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one o ...

* Pavo–Indus Supercluster *

Southern Supercluster Southern may refer to: Businesses * China Southern Airlines, airline based in Guangzhou, China * Southern Airways, defunct US airline * Southern Air, air cargo transportation company based in Norwalk, Connecticut, US * Southern Airways Express, ...

, including

Fornax Cluster The Fornax Cluster is a cluster of galaxies lying at a distance of 19 megaparsecs (62 million light-years). It has an estimated mass of solar masses, making it the second richest galaxy cluster within 100 million light-years, after the consider ...

(S373),

Dorado Dorado () is a constellation in the southern sky. It was named in the late 16th century and is now one of the 88 modern constellations. Its name refers to the dolphinfish (''Coryphaena hippurus''), which is known as ''dorado'' in Spanish, altho ...

and Eridanus clouds. The most massive galaxy clusters of the Laniakea Supercluster are

Virgo Virgo may refer to: *Virgo (astrology), the sixth astrological sign of the zodiac *Virgo (constellation), a constellation *Virgo Cluster, a cluster of galaxies in the constellation Virgo *Virgo Stellar Stream, remains of a dwarf galaxy *Virgo Supe ...

, Hydra,

Centaurus Centaurus is a bright constellation in the southern sky. One of the 88 modern constellations by area, largest constellations, Centaurus was included among the 48 constellations listed by the 2nd-century astronomer Ptolemy, and it remains one o ...

, Abell 3565, Abell 3574, Abell 3521,

Fornax Fornax () is a constellation in the southern celestial hemisphere, partly ringed by the celestial river Eridanus. Its name is Latin for furnace. It was named by French astronomer Nicolas Louis de Lacaille in 1756. Fornax is one of the 88 modern ...

, Eridanus and

. The entire supercluster consists of approximately 300 to 500 known galaxy clusters and groups. The real number may be much larger because some of these are traversing the

Zone of Avoidance The Zone of Avoidance (ZOA, ZoA), or Zone of Galactic Obscuration (ZGO), is the area of the sky that is obscured by the Milky Way. The Zone of Avoidance was originally called the Zone of Few Nebulae in an 1878 paper by English astronomer Richard ...

, an area of the sky that is partially obscured by

gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

and

dust Dust is made of fine particles of solid matter. On Earth, it generally consists of particles in the atmosphere that come from various sources such as soil lifted by wind (an aeolian process), volcanic eruptions, and pollution. Dust in homes ...

from the

galaxy, making them essentially undetectable. Superclusters are some of the universe's largest structures and have boundaries that are difficult to define, especially from the inside. Within a given supercluster, most galaxy motions will be directed inward, toward the

center of mass In physics, the center of mass of a distribution of mass in space (sometimes referred to as the balance point) is the unique point where the weighted relative position of the distributed mass sums to zero. This is the point to which a force may ...

. In the case of Laniakea, this gravitational focal point is called the

, and influences the motions of the

Local Group The Local Group is the galaxy group that includes the Milky Way. It has a total diameter of roughly , and a total mass of the order of . It consists of two collections of galaxies in a "dumbbell" shape: the Milky Way and its satellites form ...

of galaxies, where the Milky Way galaxy resides, and all others throughout the supercluster. Unlike its constituent clusters, Laniakea is not

gravitationally bound The gravitational binding energy of a system is the minimum energy which must be added to it in order for the system to cease being in a gravitationally bound state. A gravitationally bound system has a lower (''i.e.'', more negative) gravitation ...

and is projected to be torn apart by

dark energy In physical cosmology and astronomy, dark energy is an unknown form of energy that affects the universe on the largest scales. The first observational evidence for its existence came from measurements of supernovas, which showed that the univer ...

. Although the confirmation of the existence of the Laniakea Supercluster emerged in 2014, early studies in the 1980s already suggested that several of the superclusters then known might be connected. For example, South African astronomer Tony Fairall stated in 1988 that redshifts suggested that the Virgo and Hydra–Centaurus superclusters may be connected.

Location

The neighboring superclusters to the Laniakea Supercluster are the Shapley Supercluster,

Hercules Supercluster The Hercules Superclusters (SCl 160) refers to a set of two nearby superclusters of galaxies. Relative to other local superclusters, Hercules is considered particularly large, being approximately 330 Mly in diameter. The Northern Local Supervoid ...

Coma Supercluster The Coma Supercluster (SCl 117) is a nearby supercluster of galaxies comprising the Coma Cluster (Abell 1656) and the Leo Cluster (Abell 1367). Located 300 million light-years from Earth, it is in the center of the Great Wall and a part of the C ...

and

Perseus–Pisces Supercluster The Perseus–Pisces Supercluster (SCl 40) is one of the largest known structures in the universe. Even at a distance of 250 million light-years, this chain of galaxy clusters extends more than 40° across the northern winter sky. The Perseus-Pis ...

. The edges of the superclusters and Laniakea were not clearly known at the time of Laniakea's definition. Since then, the study of the edges of the supercluster and of structures beyond them has substantially improved. Laniakea is itself a constituent part of the

Pisces–Cetus Supercluster Complex The Pisces–Cetus Supercluster Complex is a galaxy filament. It includes the Laniakea Supercluster which contains the Virgo Supercluster lobe which in turn contains the Local Group, the galaxy cluster that includes the Milky Way. This filament ...

, a

galaxy filament In cosmology, galaxy filaments (subtypes: supercluster complexes, galaxy walls, and galaxy sheets) Boris V. Komberg, Andrey V. Kravtsov, Vladimir N. Lukash; "The search and investigation of the Large Groups of Quasars" ; ;R.G. Clowes; "Large Qu ...

References

External links

* Vimeo
"Laniakea Supercluster"
Daniel Pomarède, 4 September 2014—video representation of the findings of the discovery paper * YouTube
"Laniakea: Our Home Supercluster"
Nature Video, 3 September 2014—Redrawing the boundaries of the cosmic map, they redefine our home supercluster and name it Laniakea. {{Portal bar, Stars, Spaceflight, Solar System, Science 201409?? Galaxy superclusters

Name

Characteristics

Location

See also

References

Further reading

External links