The Reticulum Constellation

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. The constellation was introduced in 1621 by the German astronomer Isaac Habrecht II, who originally named it Rhombus. Nicolas Louis de Lacaille changed its name to Reticulum in the 18th century. Reticulum is one of the smallest constellations in the sky, 82nd in size, occupying an area of 114 square degrees. It is located in the first quadrant of the southern hemisphere and can be seen at latitudes between +23° and -90°. The neighbouring constellations are Dorado, Horologium and Hydrus. Reticulum belongs to the Lacaille family of constellations, along with Antila, Caelum, Circinus, Fornax, Horologium, Mensa, Microscopium, Norma, Octans, Pictor, Sculptor, and Telescopium.

Alpha Reticuli is the brightest star in the constellation. It has an apparent magnitude of 3.315 and is 161.6 light years distant from the solar system. The star has more than three times the mass of the Sun and almost 13 times the solar radius. It is approximately 240 times more luminous than the Sun. It is believed to be about 330 million years old. Alpha Reticuli is halfway between the giant and bright giant stage of evolution. It has the stellar classification of G8 II-III. It is a known X-ray source. The star has a 12th magnitude companion, CCDM J04144-6228B, at an angular separation of 48 arc seconds. The two stars share a common proper motion. Beta Reticuli is a triple star system about 100 light years away in Reticulum. It has an apparent magnitude of 3.84. The primary component in the system is an orange giant with the stellar classification K0IV SB. Epsilon Reticuli is a double star in Reticulum. It consists of an orange subgiant and a white dwarf. The primary component has the stellar classification of K2 IV and an apparent magnitude of 4.44, and the companion belongs to the stellar class D and has a visual magnitude of 12.5. The stars share a common proper motion through space and probably form a binary system. The system lies 59.5 light years from Earth. A planet with a minimum mass of 1.17 times that of Jupiter was discovered orbiting the primary star in December 2000. The planet has an orbital period of 418 days, or 1.13 years.

HD 23079 is a main sequence star belonging to the spectral class F8 or G0. It has an apparent magnitude of 7.1 and is 113.5 light years distant from the solar system. It is both larger and more massive than the Sun. The star’s age is estimated to be around 6.53 billion years, compared to the Sun’s 4.57 billion years. A giant planet was discovered orbiting the star in October 2001. The planet has a mass at least 2.45 times that of Jupiter, and orbits the star with a period of 730.6 days. HD 25171 is a yellow-white main sequence star with an apparent magnitude of 7.79. The star is approximately 179 light years distant from the solar system. HD 25171 has the stellar classification F8 V and is slightly larger and more massive than the Sun. It has 189 percent of the Sun’s luminosity and is about four billion years old, roughly the same age as the Sun. The star has a planet with a mass 0.95 times that of Jupiter orbiting it with a period of 1,845 days. HD 23127 is a yellow dwarf with the stellar classification G2V. It has an apparent magnitude of 8.58 and is approximately 320 light years distant from Earth. The star has 1.13 times the Sun’s mass and twice the Sun’s metal content. It is believed to be around seven billion years old. A planet at least 37 percent more massive than Jupiter was discovered orbiting the star on February 9, 2007. The planet has an orbital period of 1,214 days. HD 27894 is an orange dwarf star belonging to the stellar class K2 V. It has an apparent magnitude of 9.42 and is approximately 143 light years distant. A planet was discovered in the star’s orbit in 2005. The planet has a mass 0.62 times that of Jupiter and it orbits the star with a period of 17.991 days.

NGC 1559 is a barred spiral galaxy classified as a Seyfert galaxy. It has an apparent magnitude of 11 and is approximately 50 million light years distant. The galaxy is about seven times smaller than the Milky Way. It has massive spiral arms and contains regions of intense star formation. The galaxy’s disc and bar are a source of strong radio emissions. Three supernovae were observed in the galaxy in recent decades, SN 1984J in 1984, SN 1986L in 1986 and SN 2005df in 2005. The Topsy Turvy Galaxy, NGC 1313, is another barred spiral galaxy in Reticulum, which is also a starburst galaxy. It is approximately 15 million light years distant from the Milky Way and spans about 50,000 light years. The galaxy is notable because it is very uneven in shape and its axis of rotation is not located in its centre. This would usually be a result of a collision with another galaxy, but NGC 1313 appears to be alone. The galaxy was discovered by the Scottish astronomer James Dunlop on September 27, 1826. It is located near the galaxy NGC 1309 in Eridanus constellation, where a supernova was discovered in 1987. Credits: Constellation Guide, In-The-Sky.Org, Wikipedia.