Antares 3076 226025749 2008-07-16T14:24:03Z 70.157.157.115 :''This article is about the [[star]]. For other meanings, see [[Antares (disambiguation)]]'' {{Starbox begin | name=Antares A/B }} {{Starbox image | image = [[Image:Antares 3deg DSS2 WikiSky.jpg|250px]] | caption = Antares 3&deg; region on [[Digitized Sky Survey|DSS2]] all sky survey }} {{Starbox observe | epoch=[[J2000]] | constell=[[Scorpius]] | ra= {{RA|16|29|24|27.654j}}<ref name="simbad">{{cite web | title=SIMBAD Astronomical Database | work=Results for CCDM J16294-2626A/B | url=http://simbad.u-strasbg.fr/Simbad | accessdate=2006-10-23}}</ref> | dec={{DEC|-26|25|55|12.54j}}<ref name="simbad" /> | appmag_v=1.09<ref name="simbad" /> }} {{Starbox character | class= M1.5Iab-b / B2.5V<ref name="simbad" /> | b-v=1.87 | u-b=1.34 | variable=LC-type }} {{Starbox astrometry | radial_v=&minus;3.4<ref name="simbad" /> | prop_mo_ra=&minus;10.16<ref name="simbad" /> | prop_mo_dec=&minus;23.21<ref name="simbad" /> | parallax=5.40 | p_error=1.68 | parallax_footnote=<ref name="simbad" /> | absmag_v=&minus;5.28 }} {{Starbox detail | radius = 700 | mass = 15.5 | luminosity = 65,000(bolometric) | temperature = 3,500 }} {{Starbox catalog | names=α Scorpii,<ref name="simbad" /> 21 Sco,<ref name="simbad" /> Cor Scorpii, Kalb al [[Akrab]], Scorpion's Heart, Vespertilio, [[Harvard Revised catalogue|HR]] 6134,<ref name="simbad" /> [[Cordoba Durchmusterung|CD]] -26°11359,<ref name="simbad" /> [[Henry Draper catalogue|HD]] 148478,<ref name="simbad" /> [[Smithsonian Astrophysical Observatory Star Catalog|SAO]] 184415,<ref name="simbad" /> FK5 616,<ref name="simbad" /> WDS 16294-2626, CCDM J16294-2626A/B,<ref name="simbad" /> [[Hipparcos catalogue|HIP]] 80763.<ref name="simbad" /> }} {{Starbox reference | Simbad=HD+148478 }} {{Starbox end}} '''Antares''' (α Scorpii / [[alpha (letter)|Alpha]] Scorpii) is a [[red supergiant|red supergiant]] [[star]] in the [[Milky Way]] [[galaxy]] and [[list of brightest stars|the sixteenth brightest star]] in the nighttime sky (sometimes listed as fifteenth brightest, if the two brighter components of the [[Capella (star)|Capella]] quadruple star system are counted as one star). Along with [[Aldebaran]], [[Spica]], and [[Regulus]] it is one of the four brightest stars near the [[ecliptic]]. ==Properties== [[Image:Redgiants.svg|thumb|left|200px|Comparison between the red [[supergiant]] Antares and the Sun, shown as the tiny dot toward the upper right. The black circle is the size of the orbit of Mars. [[Arcturus]] is also included in the picture for size comparison.]] Antares is a [[Stellar classification|class M]] [[supergiant star]], with a diameter of approximately [[List of largest known stars|700 times that of the sun]]; if it were placed in the center of our solar system, its outer surface would lie between the orbits of Mars and Jupiter. If it were to be printed next to a picture of the sun, the sun would be just a pixel while antares would be 10 centimeters in diameter. Antares is approximately 600 [[light year]]s from our solar system. Its visual [[luminosity]] is about 10,000 times that of the [[Sun]], but because the star radiates a considerable part of its energy in the [[infrared]] part of the [[spectrum]], the bolometric luminosity equals roughly 65,000 times that of the Sun. The mass of the star is calculated to be 15 to 18 [[solar mass]]es.<ref name="kaler">James Kaler, "Antares". http://www.astro.uiuc.edu/~kaler/sow/antares.html Accessed 2/3/07.</ref> Its large size and relatively small mass give Antares a very low average density. The best time to view Antares is on or around [[May 31]] of each year, when the star is at "opposition" to the [[Sun]]. At this time, Antares rises at dusk and sets at dawn, and is thus in view all night. For approximately two to three weeks on either side of [[November 30]], Antares is not visible at all, being lost in the Sun's glare; this period of invisibility is longer in the [[Northern Hemisphere]] than in the [[Southern Hemisphere]], since the star's [[declination]] is significantly south of the celestial equator. ===Companion star=== Antares has a hot blue [[companion star]], Antares B, of spectral type B2.5 at a separation of about 2.9 [[Arcminute#Astronomy|arcseconds]], or 550 [[Astronomical unit|AUs]] at Antares' estimated distance.<ref name="kaler" /> At magnitude 5.5, it is only 1/370th as bright visually as Antares A, although it shines with 170 times the Sun's luminosity. It is normally difficult to see in small telescopes due to Antares' glare, but becomes easy in apertures over 150 mm (6 in.).<ref>Robert Burnham Jr., ''Burnham's Celestial Handbook",(New York: Dover Publications Inc., 1978), p. 1666.</ref> The companion is often described as green, but this is probably a contrast effect.<ref name="kaler" /> Antares B can be observed with a small [[telescope]] for a few seconds during lunar [[occultation]]s while Antares itself is hidden by the [[Moon]]; it was discovered during one such occultation on [[April 13]] [[1819]]. The orbit is poorly known, with an estimated [[orbital period|period]] of 878 years. [[Image:Antares-sun.gif|thumb|right|200px|Antares near the Sun, event which occurs on December 2 every year. Image from SOHO.]] ===Position on the ecliptic=== Antares is one of the 4 first magnitude stars which lie within 5° of the ecliptic and therefore can be [[Occultation|occulted]] by the Moon and rarely by the planets. On [[17 November]] [[2400]] Antares will be occulted by [[Venus]]. Every year around December 2 the Sun passes 5° north of Antares. Of the 21 first-magnitude stars, Antares now lies farthest in angular distance from any other first-magnitude star; i.e. it is possible to draw a larger circle centered around Antares without including any other first-magnitude star inside that circle, than around any other first-magnitude star. The nearest first-magnitude star to Antares is [[Alpha Centauri]], lying approximately 39°6.75&prime; away. The high [[proper motion]] of [[Alpha Centauri]] is gradually increasing this angle. Before about March 2000, [[Alpha Eridani|Achernar]] and [[Fomalhaut]] held this distinction of being the most isolated from other first-magnitude stars. ==Antares in ancient cultures== Antares' name derives from the [[Greek language|Greek]] ''Αντάρης'', meaning "(holds) against [[Ares]] (Mars)", due to the similarity of its [[red]]dish hue to the appearance of the planet [[Mars]]. It is the brightest star in the [[constellation]] [[Scorpius]]. Its distinctive [[coloration]] has made the star an object of interest to many societies throughout history. According to ancient [[Arab]] tradition, Antares is the warrior-poet [[Antarah ibn Shaddad|Antar]]'s star. Many of the old [[Egypt]]ian [[temple]]s are oriented so that the light of Antares plays a role in the ceremonies performed there. Antares was also known as ''Satevis'' in ancient [[Persia]] and was one of the four "[[royal stars]]" of the [[Iran|Persians]] around 3000 BC{{Fact|date=January 2008}}. It was also known as ''Jyeshtha'' in ancient India. In the religion of [[Stregheria]], Antares is a [[fallen angel]] and [[quarter guardian]] of the [[western gate]]. In astrology Antares is one of the [[Behenian fixed star]]s and has the symbol [[Image:Agrippa1531 corScorpii.png]].<ref name=allen>Richard Hinckley Allen, ''Star-names and their meanings'' (1936), p. 365.</ref> An old Arabic name was ''Ķalb al Άķrab'', the 'Scorpion's heart'. This had been directly translated to the [[Ancient Greek|Greek]] ''Kardia Scorpiou''/Καρδια Σκορπιου and [[Latin]] ''Cor Scorpii''.<ref name=allen/> ==See also== *[[Stars and planetary systems in fiction#Antares (Alpha Scorpii)|Antares in fiction]] ==External links== *[http://www.co-intelligence.org/newsletter/comparisons.html A comparison of the size of Antares to other celestial objects] *[http://en.scientificcommons.org/20110626 Exploring the Full Stellar Population of the upper Scorpius OB Association] *{{WikiSky}} ==References== <div class="references-small"><references/></div> [[Category:Bayer objects|Scorpii, Alpha]] [[Category:Binary stars]] [[Category:B-type main sequence stars]] [[Category:M-type supergiants]] [[Category:Scorpius constellation]] [[Category:Stars with proper names]] [[als:Antares]] [[an:Antares]] [[bg:Антарес]] [[ca:Antares]] [[cs:Antares]] [[da:Antares]] [[de:Antares]] [[et:Antares]] [[el:Αντάρης]] [[es:Antares]] [[fa:قلب عقرب]] [[fr:Alpha Scorpii]] [[gl:Antares]] [[ko:안타레스]] [[hr:Antares]] [[id:Antares]] [[it:Antares]] [[he:אנטארס]] [[lb:Antares (Stär)]] [[lt:Antaris]] [[hu:Antares]] [[nl:Antares (ster)]] [[ja:アンタレス]] [[pl:Antares]] [[pt:Antares]] [[ro:Antares]] [[ru:Антарес]] [[sk:Antares]] [[sl:Antares]] [[fi:Antares]] [[sv:Antares]] [[tr:Antares]] [[uk:Антарес]] [[zh:心宿二]]