Alpha Serpentis (α Ser / α Serpentis) is a triple star system in the constellation Serpens. Alpha Serpentis also has the traditional names Unukalhai (Unukalhay, Unuk al Hay, Unuk Elhai, Unuk), from the Arabic عنق الحية ^cunuq[u] al-ħayya[h] meaning "[the] neck", and Cor Serpentis, a Latin phrase meaning "the heart of the serpent". Alpha Serpentis is approximately 73.2 light years from Earth. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... Jump to: navigation, search The J2000. ... Jump to: navigation, search Orion is a remarkable constellation, visible from most places on the globe (but not always the whole year long). ... Serpens (the snake) is one of the 88 modern constellations, and was also one of the 48 listed by Ptolemy. ... 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. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... Jump to: navigation, search The parsec (symbol pc) is a unit of length used in astronomy. ... In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... 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. ... In astronomy, many stars are referred to simply by catalogue numbers. ... The High Precision Parallax Collecting Satellite of the Hipparcos Space Astrometry Mission was a project of the European Space Agency (ESA) dedicated to the measurement of stellar parallax and the proper motions of stars. ... In astronomy, many stars are referred to simply by catalogue numbers. ... A triple star system consists of three gravitationally bound stars. ... Jump to: navigation, search Orion is a remarkable constellation, visible from most places on the globe (but not always the whole year long). ... Serpens (the snake) is one of the 88 modern constellations, and was also one of the 48 listed by Ptolemy. ... Jump to: navigation, search Arabic (Arabic: العربية; transliterated: al-carabiyyah, less formally, عربي transliterated: carabÄ«) is the largest member of the Semitic branch of the Afro-Asiatic language family (classification: South Central Semitic) and is closely related to Hebrew and Aramaic. ... Latin was the language originally spoken in the region around Rome called Latium. ... A light year, abbreviated ly, is the distance light travels in one year: roughly 9. ... Jump to: navigation, search Earth, also known as the Earth, Terra, and (mostly in the 19th century) Tellus, is the third-closest planet to the Sun. ...

The primary star, Alpha Serpentis A is an orange K-type giant with an apparent magnitude of +2.63. It has a total luminosity of 70 times solar and a surface temerature of 4300 Kelvin. The radius of the star is some 15 times as large as that of the Sun. The magnitude +11.8 Alpha Serpentis B is 58 arcseconds from the primary, and the 13th magnitude Alpha Serpentis C lies 2.3 arcminutes from A. In astronomy, stellar classification is a classification of stars based initially on photospheric temperature and its associated spectral characteristics, and subsequenly refined in terms of other characteristics. ... According to the Hertzsprung-Russell diagram, a red giant is a large non-main sequence star of stellar classification K or M; so-named because of the reddish appearance of the cooler giants. Examples include Aldebaran and Arcturus. ... The apparent magnitude (m) of a star, planet or other heavenly body is a measure of its apparent brightness; that is, the amount of light received from the object. ... Jump to: navigation, search // In General Physics In general physics, luminosity (more properly called luminance) is the density of luminous intensity in a given direction. ... Jump to: navigation, search The kelvin (symbol: K) is the SI unit of temperature, and is one of the seven SI base units. ... A second of arc or arcsecond is a unit of angular measurement which comprises one-sixtieth of an arcminute, or 1/3600 of a degree of arc or 1/1296000 ≈ 7. ... A minute of arc, arcminute, or MOA is a unit of angular measurement, equal to one sixtieth (1/60) of one degree. ...

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• Unukalhai