Loading AI tools
Faint constellation on the celestial equator From Wikipedia, the free encyclopedia
Monoceros (Greek: Μονόκερως, "unicorn") is a faint constellation on the celestial equator. Its definition is attributed to the 17th-century cartographer Petrus Plancius. It is bordered by Orion to the west, Gemini to the north, Canis Major to the south, and Hydra to the east. Other bordering constellations include Canis Minor, Lepus, and Puppis.
This article needs additional citations for verification. (May 2020) |
Constellation | |
![]() | |
Abbreviation | Mon |
---|---|
Genitive | Monocerotis |
Pronunciation | /məˈnɒsɪrəs/, genitive /məˌnɒsɪˈroʊtɪs/ |
Symbolism | the Unicorn |
Right ascension | 7.15h |
Declination | −5.74° |
Quadrant | NQ2 |
Area | 482 sq. deg. (35th) |
Main stars | 4 |
Bayer/Flamsteed stars | 32 |
Stars with planets | 16 |
Stars brighter than 3.00m | 0 |
Stars within 10.00 pc (32.62 ly) | 4 |
Brightest star | β Mon (3.76m) |
Messier objects | 1 |
Meteor showers |
|
Bordering constellations | |
Visible at latitudes between +75° and −90°. Best visible at 21:00 (9 p.m.) during the month of February. |
Monoceros contains only a few fourth magnitude stars, making it difficult to see with the naked eye. Alpha Monocerotis has a visual magnitude of 3.93, while for Gamma Monocerotis it is 3.98.
Beta Monocerotis is a triple star system; the three stars form a fixed triangle. The visual magnitudes of the stars are 4.7, 5.2, and 6.1. William Herschel discovered it in 1781 and called it "one of the most beautiful sights in the heavens".[citation needed]
Epsilon Monocerotis is a fixed binary, with visual magnitudes of 4.5 and 6.5.
S Monocerotis, or 15 Monocerotis, is a bluish white variable star and is located at the center of NGC 2264. The variation in its magnitude is slight (4.2–4.6). It has a companion star of visual magnitude 8.
V838 Monocerotis, a variable red supergiant star, had an outburst starting on January 6, 2002; in February of that year, its brightness increased by a factor of 10,000 in one day. After the outburst was over, the Hubble Space Telescope was able to observe a light echo, which illuminated the dust surrounding the star.[1]
Monoceros also contains Plaskett's Star, a massive binary system whose combined mass is estimated[by whom?] to be almost 100 solar masses.
Monoceros is the location of the binary system Scholz's Star, host to a red dwarf primary and brown dwarf secondary; the system performed a close flypast of the Solar System approximately 70,000 years ago, travelling within 120,000 astronomical units of the Sun within the Oort cloud.[2]
One of the nearest known black holes to the Solar System is in this constellation. The binary star system A0620-00 in the constellation of Monoceros is at a distance of roughly 3,300 light-years (1,000 parsecs) away. The black hole is estimated to be 6.6 solar masses.
Monoceros contains two super-Earth exoplanets in one planetary system: CoRoT-7b was detected by the CoRoT satellite and CoRoT-7c was detected by the High Accuracy Radial Velocity Planet Searcher from ground-based telescopes. Until the announcement of Kepler-10b in January 2011, CoRoT-7b was the smallest exoplanet to have its diameter measured, at 1.58 times that of the Earth (which would give it a volume 3.95 times Earth's). Both planets in this system were discovered in 2009.
Part of the galactic plane goes through Monoceros, so background galaxies are concealed by interstellar dust. Monoceros contains many clusters and nebulae; most notable among them are:
In Western astronomy, Monoceros is a relatively modern constellation, not one of Ptolemy's 48 in the Almagest.[9] Its first certain appearance was on a globe created by the cartographer Petrus Plancius in 1612 or 1613[10] and it was later charted by German astronomer Jakob Bartsch as Unicornu on his star chart of 1624.[11]
German astronomers Heinrich Wilhelm Olbers and Ludwig Ideler[12] indicate (according to Richard Hinckley Allen's allegations) that the constellation may be older, quoting an astrological work[13] from 1564 that mentioned "the second horse between the Twins and the Crab has many stars, but not very bright"; these references may ultimately be due to the 13th century Scotsman Michael Scot, but refer to a horse and not a unicorn, and its position does not quite match. Joseph Scaliger is reported[14] to have found Monoceros on an ancient Persian sphere. French astronomer Camille Flammarion believed that a former constellation, Neper (the "Auger"), occupied the area of the sky now home to Monoceros and Microscopium, but this is disputed.[15]
Chinese asterisms Sze Fūh, the Four Great Canals; Kwan Kew; and Wae Choo, the Outer Kitchen, all lay within the boundaries of Monoceros.[15]
Seamless Wikipedia browsing. On steroids.
Every time you click a link to Wikipedia, Wiktionary or Wikiquote in your browser's search results, it will show the modern Wikiwand interface.
Wikiwand extension is a five stars, simple, with minimum permission required to keep your browsing private, safe and transparent.