Reticulum
Encyclopedia
Reticulum is a small, faint constellation
in the southern sky. Its name is Latin
for a small net
, or reticle—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, but cannot be seen from middle to northern latitudes.
in his celestial globe in 1621 , who named it Rhombus. It was later renamed by the French astronomer Nicolas Louis de Lacaille
in the eighteenth century; during his stay at the Cape of Good Hope
, he named the constellation Reticulum to commemorate the reticle in his telescope eyepiece. In 1810, the stars of Reticulum were used by William Croswell to produce the constellation Marmor Sculptile, which represented the bust of Christopher Columbus
, but this did not catch on among astronomers.
The constellation Reticulum became officially recognized during the First General Assembly of the International Astronomical Union
in 1922. The boundary for this and other constellations was drawn up by Belgian astronomer Eugène Delporte along arcs of right ascension
and declination
for epoch 1875. These were published in 1930 in the Delimination Scientifique des Constellations at the behest of the IAU.
(α) and Beta (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
.
The binary star
system Epsilon Reticuli
consists of a spectral class K2IV star being orbited by a white dwarf
. Based on parallax
measurements, this system is located about 50 light years 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
when the alleged alien abductees Betty and Barney Hill
named it as the home of their abductors.
In 2005, a type 1a supernova was discovered in the spiral galaxy NGC 1559
, located in the Reticulum 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....
in the southern sky. Its name is Latin
Latin
Latin is an Italic language originally spoken in Latium and Ancient Rome. It, along with most European languages, is a descendant of the ancient Proto-Indo-European language. Although it is considered a dead language, a number of scholars and members of the Christian clergy speak it fluently, and...
for a small net
NET
NET or Net may refer to:* Net , fibers woven in a grid-like structure* Net , any textile in which the warp and weft yarns are looped or knotted at their intersections* New Jersey Nets, a basketball team...
, or reticle—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, but cannot be seen from middle to northern latitudes.
History
This constellation was introduced by Isaac Habrecht IIIsaac Habrecht II
Isaac Habrecht II was a professor of astronomy and mathematics in Strasbourg. He was also a doctor of medicine and philosophy.- Uranography :...
in his celestial globe in 1621 , who named it Rhombus. It was later renamed by the French astronomer Nicolas Louis de Lacaille
Nicolas Louis de Lacaille
Abbé Nicolas Louis de Lacaille was a French astronomer.He is noted for his catalogue of nearly 10,000 southern stars, including 42 nebulous objects. This catalogue, called Coelum Australe Stelliferum, was published posthumously in 1763. It introduced 14 new constellations which have since become...
in the eighteenth century; during his stay at the Cape of Good Hope
Cape of Good Hope
The Cape of Good Hope is a rocky headland on the Atlantic coast of the Cape Peninsula, South Africa.There is a misconception that the Cape of Good Hope is the southern tip of Africa, because it was once believed to be the dividing point between the Atlantic and Indian Oceans. In fact, the...
, he named the constellation Reticulum to commemorate the reticle in his telescope eyepiece. 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
Christopher Columbus was an explorer, colonizer, and navigator, born in the Republic of Genoa, in northwestern Italy. Under the auspices of the Catholic Monarchs of Spain, he completed four voyages across the Atlantic Ocean that led to general European awareness of the American continents in the...
, but this did not catch on among astronomers.
The constellation Reticulum became officially recognized during the First General Assembly of the International Astronomical Union
International Astronomical Union
The International Astronomical Union IAU is a collection of professional astronomers, at the Ph.D. level and beyond, active in professional research and education in astronomy...
in 1922. The boundary for this and other constellations was drawn up by Belgian astronomer Eugène Delporte along arcs of 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...
for epoch 1875. These were published in 1930 in the Delimination Scientifique des Constellations at the behest of the IAU.
Interesting features
Only two of the stars in this constellation are brighter than visual magnitude 5: AlphaAlpha Reticuli
Alpha Reticuli is a G-type bright giant star. It is the brightest star in the constellation of Reticulum and has an apparent visual magnitude of approximately 3.343....
(α) and Beta (β) reticuli. The reddish star R Reticuli
R Reticuli
R Reticuli or S Reticuli is Mira variable star....
is a Mira variable
Mira variable
Mira variables , named after the star Mira, are a class of pulsating variable stars characterized by very red colors, pulsation periods longer than 100 days, and light amplitudes greater than one magnitude in infrared and 2.5 magnitude in visual...
. This variable was discovered by C. Ragoonatha Chary at the Madras Observatory
Madras Observatory
The Madras Observatory was founded by the British East India Company in 1786 in Chennai . For over a century it was the only astronomical observatory in India that exclusively worked on the stars. Among the astronomers at the observatory were Norman Robert Pogson, Michael Topping and John Goldingham...
in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
.
The binary star
Binary star
A binary star is a star system consisting of two stars orbiting around their common center of mass. The brighter star is called the primary and the other is its companion star, comes, or secondary...
system Epsilon Reticuli
Epsilon Reticuli
Epsilon Reticuli is a binary system approximately 59 light-years away in the constellation of Reticulum. The primary star is an orange subgiant star, while the secondary star is a white dwarf star. The primary star should be easily visible without optical aid under dark skies in the southern...
consists of a spectral class K2IV star being orbited by a white dwarf
White dwarf
A white dwarf, also called a degenerate dwarf, is a small star composed mostly of electron-degenerate matter. They are very dense; a white dwarf's mass is comparable to that of the Sun and its volume is comparable to that of the Earth. Its faint luminosity comes from the emission of stored...
. Based on parallax
Parallax
Parallax is a displacement or difference in the apparent position of an object viewed along two different lines of sight, and is measured by the angle or semi-angle of inclination between those two lines. The term is derived from the Greek παράλλαξις , meaning "alteration"...
measurements, this system is located about 50 light years from the Sun. In 2000, a planetary companion
Extrasolar planet
An extrasolar planet, or exoplanet, is a planet outside the Solar System. A total of such planets have been identified as of . It is now known that a substantial fraction of stars have planets, including perhaps half of all Sun-like stars...
was announced, orbiting the star ε Reticuli A.
Zeta Reticuli
Zeta Reticuli
Zeta Reticuli is a binary star system located about away from Earth. It is located in the constellation Reticulum, and is visible to the unaided eye in very dark skies...
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
Ufology is a neologism coined to describe the collective efforts of those who study reports and associated evidence of unidentified flying objects . UFOs have been subject to various investigations over the years by governments, independent groups, and scientists...
when the alleged alien abductees Betty and Barney Hill
Betty and Barney Hill abduction
Betty and Barney Hill were an American couple who claimed to have been abducted by extraterrestrials in a rural portion of New Hampshire on September 19–20, 1961....
named it as the home of their abductors.
In 2005, a type 1a supernova was discovered in the spiral galaxy NGC 1559
NGC 1559
NGC 1559 is a barred spiral galaxy in the constellation Reticulum. It is also a Seyfert galaxy. In 2005, a supernova was observed. Two other supernovae discovered in NGC 1559 were SN 1984J and SN 1986L...
, located in the Reticulum constellation.
Further reading
- Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.