Reticulum is a small, faint

constellation A constellation is an area on the celestial sphere in which a group of visible stars forms Asterism (astronomy), a perceived pattern or outline, typically representing an animal, mythological subject, or inanimate object. The first constellati ...

in the southern sky. Its name is

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

for a small net, or

reticle A reticle or reticule, also known as a graticule or crosshair, is a pattern of fine lines or markings built into the eyepiece of an optical device such as a telescopic sight, spotting scope, theodolite, optical microscope or the electronic v ...

—a net of crosshairs at the focus of a telescope eyepiece that is used to measure star positions. The constellation is best viewed between October and December, and save for one main star visible in ideal conditions, cannot be seen from north of the 30th parallel north.

History

A constellation in this area was introduced by Isaac Habrecht II in his

celestial globe Celestial globes show the apparent positions of the stars in the sky. They omit the Sun, Moon, and planets because the positions of these bodies vary relative to those of the stars, but the ecliptic, along which the Sun moves, is indicated. ...

in 1621, who named it ''Rhombus''. It was replaced with a somewhat different constellation by the French astronomer Nicolas Louis de Lacaille in the eighteenth century; during his stay at the

Cape of Good Hope The Cape of Good Hope ( ) is a rocky headland on the Atlantic Ocean, Atlantic coast of the Cape Peninsula in South Africa. A List of common misconceptions#Geography, common misconception is that the Cape of Good Hope is the southern tip of Afri ...

, he named the constellation le Réticule Rhomboide to commemorate the reticle in his telescope eyepiece. The name was later Latinized to Reticulum in his star catalogue ''Coelum Australe Stelliferum''. In 1810, the stars of Reticulum were used by William Croswell to produce the constellation '' Marmor Sculptile'', which represented the bust of

Christopher Columbus Christopher Columbus (; between 25 August and 31 October 1451 – 20 May 1506) was an Italians, Italian explorer and navigator from the Republic of Genoa who completed Voyages of Christopher Columbus, four Spanish-based voyages across the At ...

, but this did not catch on among astronomers. The constellation Reticulum became officially recognized during the First General Assembly of the

International Astronomical Union The International Astronomical Union (IAU; , UAI) is an international non-governmental organization (INGO) with the objective of advancing astronomy in all aspects, including promoting astronomical research, outreach, education, and developmen ...

in 1922. The boundary for this and other constellations was drawn up by Belgian astronomer Eugène Delporte along arcs of

right ascension Right ascension (abbreviated RA; symbol ) is the angular distance of a particular point measured eastward along the celestial equator from the Sun at the equinox (celestial coordinates), March equinox to the (hour circle of the) point in questio ...

and

declination In astronomy, declination (abbreviated dec; symbol ''δ'') is one of the two angles that locate a point on the celestial sphere in the equatorial coordinate system, the other being hour angle. The declination angle is measured north (positive) or ...

for epoch 1875. These were published in 1930 in the ''Delimination Scientifique des Constellations'' at the behest of the IAU.

Features

Only two of the stars in this constellation are brighter than

visual magnitude Apparent magnitude () is a measure of the brightness of a star, astronomical object or other celestial objects like artificial satellites. Its value depends on its intrinsic luminosity, its distance, and any extinction of the object's light ca ...

Alpha Alpha (uppercase , lowercase ) is the first letter of the Greek alphabet. In the system of Greek numerals, it has a value of one. Alpha is derived from the Phoenician letter ''aleph'' , whose name comes from the West Semitic word for ' ...

(α) and

Beta Beta (, ; uppercase , lowercase , or cursive ; or ) is the second letter of the Greek alphabet. In the system of Greek numerals, it has a value of 2. In Ancient Greek, beta represented the voiced bilabial plosive . In Modern Greek, it represe ...

(β) reticuli. The reddish star R Reticuli is a Mira variable. This variable was discovered by C. Ragoonatha Chary at the Madras Observatory in

India India, officially the Republic of India, is a country in South Asia. It is the List of countries and dependencies by area, seventh-largest country by area; the List of countries by population (United Nations), most populous country since ...

. The

binary star A binary star or binary star system is a system of two stars that are gravitationally bound to and in orbit around each other. Binary stars in the night sky that are seen as a single object to the naked eye are often resolved as separate stars us ...

system Epsilon Reticuli consists of a spectral class K2IV star being orbited by a

white dwarf A white dwarf is a Compact star, stellar core remnant composed mostly of electron-degenerate matter. A white dwarf is very density, dense: in an Earth sized volume, it packs a mass that is comparable to the Sun. No nuclear fusion takes place i ...

. Based on

parallax Parallax is a displacement or difference in the apparent position of an object viewed along two different sightline, lines of sight and is measured by the angle or half-angle of inclination between those two lines. Due to perspective (graphica ...

measurements, this system is located about 50

light year A light-year, alternatively spelled light year (ly or lyr), is a unit of length used to express astronomical distance, astronomical distances and is equal to exactly , which is approximately 9.46 trillion km or 5.88 trillion mi. As defined by t ...

s from the Sun. In 2000, a planetary companion was announced, orbiting the star ε Reticuli A. Zeta Reticuli is a wide binary star system, with both members being similar to the Sun. It is located at a distance of about 39 light years. This system gained some notoriety in

ufology Ufology, sometimes written UFOlogy ( or ), is the investigation of unidentified flying objects (UFOs) by people who believe that they may be of extraordinary claims, extraordinary origins (most frequently of extraterrestrial hypothesis, extrate ...

when the alleged alien abductees Betty and Barney Hill named it as the home of their abductors. In 2005, a

type Ia supernova A Type Ia supernova (read: "type one-A") is a type of supernova that occurs in binary systems (two stars orbiting one another) in which one of the stars is a white dwarf. The other star can be anything from a giant star to an even smaller white ...

was discovered in the spiral galaxy NGC 1559, located in the constellation. The dwarf galaxy Reticulum II is enriched in

r-process In nuclear astrophysics, the rapid neutron-capture process, also known as the ''r''-process, is a set of nuclear reactions that is responsible for nucleosynthesis, the creation of approximately half of the Atomic nucleus, atomic nuclei Heavy meta ...

heavy elements. The Horologium-Reticulum Supercluster is a galaxy supercluster that ranges from 700 million to 1.2 billion light-years from Earth.

References

Works cited

External links

The Deep Photographic Guide to the Constellations: Reticulum

{{DEFAULTSORT:Reticulum Southern constellations Constellations listed by Lacaille

History

Features

See also

References

Works cited

External links