Regulus (α Leo / α Leonis / Alpha Leonis) is the brightest star in the constellation Leo and one of the brightest stars in the nighttime sky. In astronomy, an epoch is a moment in time for which celestial coordinates or orbital elements are specified. ... This article or section does not adequately cite its references or sources. ... Leo (IPA: , Latin: , symbol , ) is a constellation of the zodiac. ... Equatorial Coordinates Right ascension (abbrev. ... In astronomy, declination (abbrev. ... The apparent magnitude (m) of a star, planet or other celestial body is a measure of its apparent brightness as seen by an observer on Earth. ... 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. ... In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... In astronomy, the color index is a simple numerical expression that determines the color of an object, which in the case of a star gives its temperature. ... Most stars are of almost constant luminosity. ... Illustration of the use of optical wavelength interferometry to determine precise positions of stars. ... 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 (from Old English gÄ“r) 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 (from Old English gÄ“r) is the time between two recurrences of an event related to the orbit of the Earth around the Sun. ... This does not adequately cite its references or sources. ... A milliarcsecond (m, mas) , or a thoundsanth of an arcsecond. ... Distance is a numerical description of how far apart objects are at any given moment in time. ... A light-year or lightyear (symbol: ly) is a unit of measurement of length, specifically the distance light travels in vacuum in one Julian year. ... Stellar parallax motion 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, in the absence of interstellar extinction. ... Unsolved problems in physics: What causes anything to have mass? The U.S. National Prototype Kilogram, which currently serves as the primary standard for measuring mass in the U.S. Mass is the property of a physical object that quantifies the amount of matter and energy it is equivalent to. ... In astronomy, the solar mass is a unit of mass used to express the mass of stars and larger objects such as galaxies. ... Circle illustration In classical geometry, a radius (plural: radii) of a circle or sphere is any line segment from its center to its boundary. ... 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. ... Fig. ... The Kelvin scale is a thermodynamic (absolute) temperature scale where absolute zero—the lowest possible temperature where nothing could be colder and no heat energy remains in a substance—is defined as zero kelvin (0 K). ... The globular cluster M80. ... A sphere rotating around its axis. ... STAR is an acronym for: Organizations Society for Telescopy, Astronomy, and Radio, a non-profit New Jersey astronomy club. ... A year (from Old English gÄ“r) 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. ... 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. ... In astronomy, many stars are referred to simply by catalogue numbers. ... 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). ... The Hipparcos and Tycho Catalogues (Tycho-1) are the primary products of the European Space Agencys astrometric mission, Hipparcos. ... SIMBAD (the Set of Identifications, Measurements, and Bibliography for Astronomical Data) is a database of astronomical information about objects within the Milky Way. ... Alpha (uppercase Α, lowercase α) is the first letter of the Greek alphabet. ... This article or section does not adequately cite its references or sources. ... Leo (IPA: , Latin: , symbol , ) is a constellation of the zodiac. ... Bright stars can be bright because they produce more light, because they are closer to us, or both. ...

Regulus is approximately 77.5 light years from Earth's Solar System. It's name is Latin for "prince" or "little king". It is also known as Qalb Al Asad, from Arabic قلب الأسد qalb[u] al-´asad, meaning "the heart of the lion." This phrase is sometimes approximated as Kabelaced, or translated into Latin as Cor Leonis. In Hindu astronomy, Regulus corresponds to the Nakshatra Magha. Regulus is considered the last first magnitude star in the sky because the next brightest star, Adhara, has a magnitude of 1.50, officially making it a second magnitude star. Of the brightest stars in the sky, Regulus is closest to the ecliptic, and the sun makes its closest approach around August 23 of each year. This fact also means that Regulus is regularly occulted by the Moon. It's known as 轩辕十四 (the Fourteenth Star of Xuanyuan) in Chinese. Xuanyuan is the name of Yellow Emperor. A light-year or lightyear (symbol: ly) is a unit of measurement of length, specifically the distance light travels in vacuum in one Julian year. ... Adjectives: Terrestrial, Terran, Telluric, Tellurian, Earthly Atmosphere Surface pressure: 101. ... Major features of the Solar System (not to scale; from left to right): Pluto, Neptune, Uranus, Saturn, Jupiter, the asteroid belt, the Sun, Mercury, Venus, Earth and its Moon, and Mars. ... Latin is an ancient Indo-European language originally spoken in Latium, the region immediately surrounding Rome. ... Arabic ( or just ) is the largest living member of the Semitic language family in terms of speakers. ... This article discusses the adherents of Hinduism. ... A page from the Hindu calendar 1871-72. ... A nakshatra (Devanagari: नक्षत्र) or lunar mansion is one of the 27 or 28 divisions of the sky, identified by the prominent star(s) in them, that the Moon passes through during its monthly cycle, as used in Hindu astronomy and astrology. ... Maagha (Hindi: माघ maagh) is a month of the Hindu calendar. ... Adhara (ε CMa / ε Canis Majoris / Epsilon Canis Majoris), is the second brightest star in the constellation Canis Major, and one of the brightest stars in the nighttime sky. ... In this July, 1997 still frame captured from video, the bright star Aldebaran has just reappeared on the dark limb of the waning crescent moon in this predawn occultation. ... Yellow Emperor The Yellow Emperor or Huang Di (Traditional Chinese: , Simplified Chinese: , pinyin: huángdì) is a legendary Chinese sovereign and cultural hero who is said to be the ancestor of all Han Chinese. ...

Regulus has about 3.5 times the Sun's mass, and is a young star only a few hundred million years old. It is spinning extremely rapidly, with a rotation period of only 15.9 hours, which causes it to have a highly oblate shape. This results in gravity darkening: its poles are considerably hotter and five times as bright (per unit surface area) than its equator. If it were rotating only 16% faster the centripetal force of gravity would not be enough to keep it from tearing itself apart. The Sun is the star at the center of the Solar System. ... An oblate spheroid is ellipsoid having a shorter axis and two equal longer axes. ... Gravity darkening is a phenomenon occurrent in some stars, such as the star Regulus in the Leo constellation, where the star is rotating so rapidly that centrifugal force upon the star gives it an oblong, egg-like shape. ... The centripetal force is the external force required to make a body follow a circular path at constant speed. ...

This star has a pair of small, faint companions in the form of a binary star system. These stars are separated by about 100 AUs and orbit each other every 2,000 years. This pair is separated from the much larger Regulus A by about 4,200 AU and orbit the main star with a period of over 130,000 years. Artists impression of a binary system consisting of a black hole, with an accretion disc around it, and a main sequence star. ... Look up Au, au in Wiktionary, the free dictionary. ...

Astrology

Regulus was one of the four "royal stars" of the Persians around 3000 BC. It was one of the fifteen Behenian stars to medieval astrologers, associated with granite, mugwort, and the kabbalistic symbol . The four Royal stars or Guardians of the Sky were a group of stars noticed by the Persian astrologers around 3000 BC and used as a rudimentary season calendar. ... The Persians of Iran (officially named Persia by West until 1935 while still referred to as Persia by some) are an Iranian people who speak Persian (locally named Fârsi by native speakers) and often refer to themselves as ethnic Iranians as well. ... (31st century BC - 30th century BC - 29th century BC - other centuries) (4th millennium BC - 3rd millennium BC - 2nd millennium BC) Events 2925 - 2776 BC - First Dynasty wars in Egypt 2900 BC - Beginning of the Early Dynastic Period I in Mesopotamia. ... List of Behenian Stars Caput Algol (Algols head, associated with the head of Gorgona), Pleiades (actually, several stars), Aldebaran, Alhayhoch, Canis Maior (actually, a constellation, like the next one), Canis Minor, Cor Leonis (Hearth of the Lion), Cauda Urse (Tail of the Bear), Ala Corvi (Wing of the crow... The Middle Ages formed the middle period in a traditional schematic division of European history into three ages: the classical civilization of Antiquity, the Middle Ages, and modern times. ... An astrologer practices one or more forms of astrology. ... Quarrying granite for the Mormon Temple, Utah Territory. ... Binomial name Artemisia vulgaris L. Mugwort or Common Wormwood (Artemisia vulgaris) is a species from the daisy family Asteraceae. ... The tree of life Kabbalah (קבלה Reception, Standard Hebrew Qabbala, Tiberian Hebrew Qabbālāh; also written variously as Cabala, Cabalah, Cabbala, Cabbalah, Kabala, Kabalah, Kabbala, Qabala, Qabalah) is a religious philosophical system claiming an insight into divine nature. ... Image File history File links after Agrippa File history Legend: (cur) = this is the current file, (del) = delete this old version, (rev) = revert to this old version. ...

In the religion of Stregheria, Regulus is a fallen angel and quarter guardian of the southern gate. Ways of the Strega published in 1994, described Raven Grimassis view of Stregheria and popularized Italian-based religious witchcraft. ... It has been suggested that Evil Angels be merged into this article or section. ...

See also

• Regulus in fiction

The planetary systems of stars other than the Sun and its Solar System are a staple element in much science fiction. ...

References

• Fred Schaaf, "Secrets of the Lion's heart", Sky & Telescope, April 2006.

Sky & Telescope is a monthly magazine providing articles and information on all aspects of astronomy, space exploration, telescope equipment, and amateur telescope making and use. ... April 2006 : ← - January - February - March - April - May - June - July - August - September - October - November - December- → Marcos Pontes, Brazils first astronaut, reaches the International Space Station. ...

External links

• Astronomers: ‘Bullet star’ shines 350 times brighter than the sun
• Portrait of a Star on the Edge
• Egg-Shaped Regulus is Spinning Fast
• Regulus as Astronomy Picture of the Day of 19th june 2006
• Regulus 3. SolStation. Retrieved on December 1, 2005.