Epsilon Orionis

Alnilam lights up NGC 1990. Photograph by Glen Youman.
Observation data Epoch J2000
Constellation	Orion
Right ascension	05h 36m 12.8s
Declination	-01° 12′ 06.9″
Apparent magnitude (V)	1.69
Characteristics
Spectral type	B0 Ia
B-V color index	-0.19
U-B color index	-1.04
Variable type	?
Astrometry
Radial velocity (Rv)	26 km/s
Proper motion (μ)	RA: 1.49 mas/yr Dec.: -1.06 mas/yr
Parallax (π)	2.43 ± 0.91 mas
Distance	1,342 ly (412 pc)
Absolute magnitude (MV)	-6.39
Details
Mass	40 M☉
Radius	26 R☉
Luminosity	375,000 L☉
Temperature	25,000 K
Metallicity	?
Rotation	~87 km/s.
Age	4 × 106 years
Other designations
Alnilam, Alnihan, Alnitam, 46 Orionis, HR 1903, BD -01°969, HD 37128, SAO 132346, FK5 210, HIP 26311.

Epsilon Orionis (ε Ori / ε Orionis) is a large blue star in the constellation of Orion. It also has the traditional name Alnilam. Its Flamsteed designation is 46 Orionis. This image shows Alnilam lighting up NGC 1990. ... In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Orion, a constellation often referred to as The Hunter, is a prominent constellation, perhaps the best-known in the sky. ... Right ascension (RA; symbol α: Greek letter alpha) is the astronomical term for one of the two coordinates of a point on the celestial sphere when using the equatorial coordinate system. ... In astronomy, declination (dec) is one of the two coordinates of the equatorial coordinate system, the other being either right ascension or hour angle. ... // Headline text HEY!! HOW ARE YOU ALL?? Its nice of you to come read this page. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequently refined in terms of other characteristics. ... Shanil Davendra Singh rules 4 life! ... Shanil Davendra Singh rules 4 life! ... Most stars are of almost constant luminosity. ... This article does not cite its references or sources. ... Radial velocity is the velocity of an object in the direction of the line of sight. ... kilometre per second is an SI derived unit of both speed (scalar) and velocity (vector), signified by the symbol km/s or km s-1. ... The proper motion of a star is the motion of the position of the star in the sky (the change in direction in which we see it, as opposed to the radial velocity) after eliminating the improper motions of the stars, which affect their measured coordinates but are not real... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... Parallax (Greek: παραλλαγή (parallagé) = alteration) is the change of angular position of two stationary points relative to each other as seen by an observer, due to the motion of an observer. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... The distance between two points is the length of a straight line segment between them. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... The parsec (symbol pc) is a unit of length used in astronomy. ... In astronomy, absolute magnitude is the apparent magnitude, m, an object would have if it were at a standard luminosity distance away from us. ... Mass is a property of a physical object that quantifies the amount of matter it contains. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... RADIUS (Remote Authentication Dial In User Service) is an AAA (authentication, authorization and accounting) protocol for applications such as network access or IP mobility. ... In astronomy, the solar radius is a unit of length used to express the size of stars and larger objects such as galaxies. ... Luminosity has different meanings in several different fields of science. ... The solar luminosity, , is a unit of luminosity (power emitted in the form of photons) conventionally used by astronomers to give the luminosities of stars. ... Temperature is also the name of a song by Sean Paul. ... The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... In astronomy, the metallicity of an object is the proportion of its matter made up of chemical elements other than hydrogen and helium. ... Rotation of a plane, seen as the rotation of the terrain relative to the plane (exposure time 1. ... The Pleiades star cluster A star is a massive body of plasma in outer space that is currently producing or has produced energy through nuclear fusion. ... A year is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Henry Draper Catalogue is an astronomy catalogue with astrometric and spectroscopic data about more than 225,000 stars. ... The Smithsonian Astrophysical Observatory (SAO) is a research institute of the Smithsonian Institution headquartered in Cambridge, Massachusetts, where it is joined with the Harvard College Observatory (HCO) to form the Harvard-Smithsonian Center for Astrophysics (CfA). ... In astronomy, many stars are referred to simply by catalogue numbers. ... The Pleiades star cluster A star is a massive body of plasma in outer space that is currently producing or has produced energy through nuclear fusion. ... Orion is a remarkable constellation, visible from most places on the globe at one time or another during the year. ... Orion, a constellation often referred to as The Hunter, is a prominent constellation, perhaps the best-known in the sky. ... Flamsteed designations for stars are similar to Bayer designations, except that they use numbers instead of Greek letters. ...

It is the 30th brightest star in the sky, the 4th brightest in Orion, and a blue-white supergiant. It is the middle star of Orion's belt. Bright stars can be bright because they produce more light, because they are closer to us, or both. ... Blue supergiants are supergiant stars of spectral type O. They are extremely hot and bright, with surface temperatures of between 20,000 - 50,000°C. They typically have 10 to 50 solar masses on the Hertzsprung-Russell diagram, and can have radii up to about 25 solar radii. ... Orion, a constellation often referred to as The Hunter, is a prominent constellation, perhaps the best-known in the sky. ...

It is also one of the 57 stars used in celestial navigation. For middle latitudes, it is at its highest point in the sky around 10 p.m. on December 10. Celestial Navigation is the 15th episode of The West Wing. ... December 10 is the 344th day (345th in leap years) of the year in the Gregorian calendar. ...

Alnilam's relatively simple spectrum has made it useful for studying the interstellar medium. Within the next million years, this star may turn into a red supergiant and explode as a supernova. It is surrounded by a molecular cloud, NGC 1990, which it brightens to make a reflection nebula. Its stellar winds may reach up to 2000 km/s, causing it to lose mass about 20 million times more rapidly than the Sun. The distribution of ionized hydrogen (known by astronomers as H II (aitch two) from old spectroscopic terminology) in the parts of the Galactic interstellar medium visible from the Earths northern hemisphere (from the Wisconsin H-Alpha Mapper Survey) In astronomy, the interstellar medium (or ISM) is the matter (interstellar... Red supergiants are supergiant stars of spectral type M. See also Blue supergiant Categories: Star stubs | Star types | Red supergiants ... Multiwavelength X-ray image of the remnant of Keplers Supernova, SN 1604. ... A Molecular cloud is a type of interstellar cloud whose density and size permits the formation of molecular hydrogen, H2. ... In astronomy, reflection nebulae are clouds of dust which are simply reflecting the light of a nearby star or stars. ... A solar wind is a stream of particles (mostly high-energy protons ~ 500 keV) which are ejected from the upper atmosphere of a star (in the case of a star other than the Earths Sun, it may be called a stellar wind instead). ... The velocity of an object is simply its speed in a particular direction. ... Mass is a property of a physical object that quantifies the amount of matter it contains. ...

Other names and history

The name Alnilam derives from the Arabic النظام an-niżām, related to the word نظم nażm "string of pearls". Related spellings are Alnihan and Alnitam: all three variants are evidently mistakes in transliteration or copy errors. Countries where Arabic is spoken. ...

Various other names have been used to refer to Orion's belt, the line of three stars formed by Alnitak, Alnilam, and Mintaka. They include: This article needs to be cleaned up to conform to a higher standard of quality. ... Mintaka, also known as δ Orionis, is one of the three stars of the belt of the Orion constellation. ...

• The Weighing Beam (Chinese mythology)
• Jacob's Staff, Peter's Staff, the Three Magi, or the Three Kings (the Bible)
• Freya's Staff (Norse mythology)
• Väinämöinen's Scythe (Kalevala)
• Kalevan Sword (Finnish mythology)

These stars also influenced the construction of the Pyramids of Giza. At the moment this article is only a list. ... The Gutenberg Bible owned by the United States Library of Congress The Bible (Hebrew: תנ״ך tanakh, Greek: η Βίβλος hē biblos) (sometimes The Holy Bible, The Book, Work of God, The Word, The Good Book or Scripture), from Greek (τα) βίβλια, (ta) biblia, (the) books, is the name used by Jews and Christians for their... Freya, in an illustration to Wagners operas by Arthur Rackham. ... Norse or Scandinavian mythology comprises the pre-Christian religion, beliefs and legends of the Scandinavian people, including those who settled on Iceland, where the written sources for Norse mythology were assembled. ... Illustration from the Kalevala, by Akseli Gallen-Kallela 1896. ... The Kalevala is an epic poem which Elias Lönnrot compiled from Finnish folk lore in the 19th century. ... Finnish mythology consisted of a belief in various indigenous nature spirits and gods, mixed with the more shamanic influences of the Sami people in the north and the Baltic and Viking influences from the south and the west. ... The Giza pyramid field, viewed from the southwest. ...