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

galaxy A galaxy is a Physical system, system of stars, stellar remnants, interstellar medium, interstellar gas, cosmic dust, dust, and dark matter bound together by gravity. The word is derived from the Ancient Greek, Greek ' (), literally 'milky', ...

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 tu ...

that is home to the

Milky Way The Milky Way or Milky Way Galaxy is the galaxy that includes the Solar System, with the name describing the #Appearance, galaxy's appearance from Earth: a hazy band of light seen in the night sky formed from stars in other arms of the galax ...

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 is a public college and university system in Hawaii. The system confers associate, bachelor's, master's, and doctoral degrees through three universities, seven community colleges, an employment training center, ...

, Hélène Courtois of the University of Lyon, Yehuda Hoffman of the

Hebrew University of Jerusalem The Hebrew University of Jerusalem (HUJI; ) is an Israeli public university, public research university based in Jerusalem. Co-founded by Albert Einstein and Chaim Weizmann in July 1918, the public university officially opened on 1 April 1925. ...

, and Daniel Pomarède of CEA

Université Paris-Saclay Paris-Saclay University (, ) is a combined Research institute, technological research institute and Public university, public research university in Orsay, France. Paris-Saclay was established in 2019 after the merger of four technical ''grandes ...

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

Virgo Virgo may refer to: Arts and entertainment * Virgo (film), a 1970 Egyptian film * Virgo (character), several Marvel Comics characters * Virgo Asmita, a character in the manga ''Saint Seiya: The Lost Canvas'' * ''Virgo'' (album), by Virgo Four, ...

and Hydra-Centaurus Supercluster as appendages, the former being the prior defined local supercluster. 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, who used knowledge of the sky to navigate the

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

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

Virgo Supercluster The Local Supercluster (LSC or LS), or Virgo Supercluster is a formerly defined supercluster containing the Virgo Cluster and Local Group, which itself contains the Milky Way and Andromeda galaxies, as well as others. At least 100 galaxy group ...

, the part in which the Milky Way resides. * Hydra–Centaurus Supercluster ** the Great Attractor, 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) ** Norma Lizbeth Ramos, a Mexican bullying victim Astronomy *Norma (constellation) * 555 Norma, a minor asteroid * Cygnus Arm or Norma Arm, a spiral ...

** Antlia Wall, known as Hydra Supercluster ** Centaurus Supercluster * Pavo–Indus Supercluster *

Southern Supercluster The Southern Supercluster is a nearby supercluster located around in the constellations of Cetus, Fornax, Eridanus (constellation), Eridanus, Horologium (constellation), Horologium, and Dorado. It was first identified in 1953 by Gérard de Vaucou ...

, 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 mahi-mahi (''Coryphaena hippurus''), which is known as ''dorado'' ("golden") in Sp ...

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

, 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 ...

, Abell 3565, Abell 3574, Abell 3521,

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

, 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, an area of the sky that is partially obscured by gas and

dust Dust is made of particle size, 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 processes, aeolian process), Types of volcan ...

from the

galaxy, making them essentially undetectable. Superclusters are some of the

universe The universe is all of space and time and their contents. It comprises all of existence, any fundamental interaction, physical process and physical constant, and therefore all forms of matter and energy, and the structures they form, from s ...

'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 barycenter or balance point) is the unique point at any given time where the weight function, weighted relative position (vector), position of the d ...

. This gravitational focal point, in the case of Laniakea, is called the Great Attractor, and influences the motions of the

Local Group The Local Group is the galaxy group that includes the Milky Way, where Earth is located. 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 ...

of galaxies, where the Milky Way galaxy resides, and all others throughout the supercluster. Unlike its constituent clusters, Laniakea is not gravitationally bound and is projected to be torn apart by

dark energy In physical cosmology and astronomy, dark energy is a proposed form of energy that affects the universe on the largest scales. Its primary effect is to drive the accelerating expansion of the universe. It also slows the rate of structure format ...

. 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 The Shapley Supercluster or Shapley Concentration (SCl 124) is the largest concentration of galaxies in our universe that forms a gravitationally interacting unit, thereby pulling itself together instead of expanding with the universe. It appears ...

, Hercules Supercluster, Coma Supercluster, 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– ...

. 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, a

galaxy filament In cosmology, galaxy filaments are the largest known structures in the universe, consisting of walls of galactic superclusters. These massive, thread-like formations can commonly reach 50 to 80 megaparsecs ()—with the largest found to date b ...

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, Astronomy, Science 201409?? Galaxy superclusters Solar System

Name

Characteristics

Location

See also

References

Further reading

External links