Constellations of the Month: January – Reticulum:
We continue January with the constellation of Reticulum, “The Reticle” or “Small Net.”

Reticulum constellation map courtesy of Openverse

Reticulum, “The Reticle” or “Small Net” – Reticulum is a constellation is situated in the southern hemisphere. Its designation derives from the Latin term for “the Reticle.”  It is among the 14 constellations established by the French astronomer Nicolas Louis de Lacaille during the 18^th century. The Reticulum is a diminutive network located at the center of a telescope’s eyepiece, facilitating the measurement of star positions. This constellation was first introduced in 1621 by the German astronomer Isaac Habrecht II, who initially referred to it as Rhombus. In the 18^th century, Nicolas Louis de Lacaille renamed it Reticulum. The constellation known as Reticulum is pronounced /rɪˈtɪkjʊləm/. In English, it is referred to as the Reticle. The genitive form of Reticulum, which is utilized in the naming of stars, is Reticuli, pronounced /rɪˈtɪkjʊlaɪ/. The three-letter abbreviation, established by the International Astronomical Union (IAU) in 1922, is Ret.

Phot-43a-06 courtesy of Openverse

Key points regarding Reticulum:

• Meaning: The term “Reticulum” translates to “The Reticle” or “Small Net” in Latin.
• Notable stars: The Reticulum constellation has five stars confirmed to have planets but no Messier objects. The brightest star, Rhombus (Alpha Reticuli), has an apparent magnitude of 3.315 and is about 160 light-years from Earth. It is a source of X-rays and classified as an evolved yellow giant star, being 3.12 times the mass and 12.09 times the radius of the Sun. Its luminosity is around 103 times greater than that of the Sun, with a surface temperature of 5,288 K and an estimated age of 330 million years. Alpha Reticuli has a companion star, CCDM J04144-6228B, with a magnitude of 12. Beta Reticuli is a triple star system about 100 light years away, and Epsilon Reticuli is a double star system about 59. 5 light years away, hosting a planet. Other stars include red giants Gamma and Delta Reticuli, binary systems Kappa and Zeta Reticuli, and yellow giant Eta Reticuli. Theta Reticuli is a double star, while R Reticuli is a distant red Mira variable star expected to become a white dwarf in the future.
• Other features: Reticulum is home to two significant deep sky objects: the barred spiral galaxy NGC 1559 and NGC 1313, which is commonly referred to as the Topsy Turvy Galaxy. Reticulum also features Tupi (HD 23079), named after indigenous Brazilians, and the planet is named Guarani., a main sequence star of type F9.5V, located 109.2 light-years away and shining at magnitude 7.12, which is too faint to be seen by the naked eye. It has a mass of 1.01 solar masses and a radius of 1.08 solar radii, with an effective temperature of 6,003 K and a luminosity of 1.372 solar luminosities. The star is about 5.1 billion years old. A giant planet, HD 23079B, was discovered in October 2001, with a mass at least 2.41 times that of Jupiter, orbiting the star every 724.5 days at a distance of 1.586 AU. HD 25171 is a yellow-white main sequence star, with a magnitude of 7.79, located 179 light years away. It is slightly larger than the Sun, with 189% of the Sun’s luminosity and an age of about four billion years. A planet with a mass of 0.95 times that of Jupiter orbits it every 1,845 days. The Topsy Turvy Galaxy, NGC 1313, is a barred spiral galaxy located in Reticulum, about 15 million light years from the Milky Way and measuring roughly 50,000 light years across. It has an uneven shape and an off-center rotation axis, suggesting a possible collision, yet it appears to be isolated. Discovered by James Dunlop on September 27, 1826, it is near NGC 1309 in the Eridanus constellation, where a supernova was found in 1987. Additionally, there are no meteor showers linked to this constellation.
• Mythology: The Reticulum is a diminutive network located at the center of a telescope’s eyepiece, facilitating the measurement of star positions. This constellation was first introduced in 1621 by the German astronomer Isaac Habrecht II, who initially referred to it as Rhombus. In the 18^th century. The French astronomer Nicolas Louis de Lacaille renamed it to le Réticule Rhomboide, or Reticulum, in honor of the reticle in his telescope, which he utilized to determine star positions during his expedition to the Cape of Good Hope in the early 1750’s. The International Astronomical Union officially recognized the constellation in 1922.
• Visibility: Reticulum ranks as one of the smallest constellations, positioned 82nd in terms of size, and covering an area of 114 square degrees. It is situated in the first quadrant of the southern hemisphere (SQ1) and is observable at latitudes ranging from +23° to -90°. The constellations that border Reticulum include Dorado, Horologium, and Hydrus. Reticulum is part of the Lacaille family of constellations, which also includes Antlia, Caelum, Circinus, Fornax, Horologium, Mensa, Microscopium, Norma, Octans, Pictor, Sculptor, and Telescopium.

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Constellations:

Not Too Far Away courtesy of Openverse

Constellations of the Month:
January – Reticulum

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