The Horologium Supercluster (also known as Horologium-Reticulum Supercluster, consisting of SCl 48 and SCl 49) is a massive supercluster

Supercluster

Superclusters are large groups of smaller galaxy groups and clusters and are among the largest known structures of the cosmos. They are so large that they are not gravitationally bound and, consequently, partake in the Hubble expansion.-Existence:...

, about 550 million light-years across and has a mass of 10¹⁷ solar masses

Sun

The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

. It is centered on coordinates right ascension

Right ascension

Right ascension is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. The other coordinate is the declination.-Explanation:...

  and declination

Declination

In astronomy, declination is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. Declination in astronomy is comparable to geographic latitude, but projected onto the celestial sphere. Declination is measured in degrees north and...

 , and spans an angular area of 12° × 12°.

The nearest part of the supercluster is 700 million light-year

Light-year

A light-year, also light year or lightyear is a unit of length, equal to just under 10 trillion kilometres...

s (z=0.063) away from us (mainly the clusters near the bottom of the picture) but the far end of it is 1.2 billion light-years (mainly the clusters at the top) in the constellation

Constellation

In modern astronomy, a constellation is an internationally defined area of the celestial sphere. These areas are grouped around asterisms, patterns formed by prominent stars within apparent proximity to one another on Earth's night sky....

s Horologium

Horologium

Horologium is a small and faint constellation in the southern sky . Its name is Latin for clock. It was created in the 18th century by Abbé Nicolas Louis de Lacaille, who originally named it Horologium Oscillitorium after the pendulum clock to honour its inventor, Christiaan Huygens...

 and Eridanus

Eridanus (constellation)

Eridanus is a constellation. It is represented as a river; its name is the Ancient Greek name for the Po River. It was one of the 48 constellations listed by the 2nd century astronomer Ptolemy, and it remains one of the 88 modern constellations. It is the sixth largest of the modern...

. The Horologium supercluster has about 5,000 galaxy groups (30,000 giant galaxies and 300,000 dwarf galaxies). It includes the cluster Abell 3266

Abell 3266

Abell 3266 is a galaxy cluster in the southern sky. It is part of the Horologium-Reticulum supercluster. The galaxy cluster is one of the largest in the southern sky, and one of the largest mass concentrations in the nearby universe....

. The map on the right shows every galaxy brighter than magnitude 17.

See also

• Horologium cluster
  Horologium Cluster
  The Horologium cluster is a cluster of galaxies which is a part of the Horologium Supercluster. It is 900 million light years away from the Milky Way....
  
  
• List of galaxies
• List of nearest stars
• Universe
  Universe
  The Universe is commonly defined as the totality of everything that exists, including all matter and energy, the planets, stars, galaxies, and the contents of intergalactic space. Definitions and usage vary and similar terms include the cosmos, the world and nature...
  
  
• Space
  Space
  Space is the boundless, three-dimensional extent in which objects and events occur and have relative position and direction. Physical space is often conceived in three linear dimensions, although modern physicists usually consider it, with time, to be part of a boundless four-dimensional continuum...
  
  

External links

• The Horologium Supercluster from An Atlas of the Universe