View source for Spica

{{Short description|Star in the constellation Virgo}}
{{About|the star}}
{{Starbox begin
|name = Spica
}}
{{Starbox image
 | image=
{{Location mark
|image=Virgo constellation map.svg
|float=center
|alt=
|label=
|position=right
|width=280
|mark=Red circle.svg
|mark_width=12
|mark_link=Spica
|x=360|y=704
}}
|caption=Location of Spica (circled)
}}
{{Starbox observe
|epoch    = J2000
|constell = [[Virgo (constellation)|Virgo]]
|pronounce= {{IPAc-en|ˈ|s|p|aɪ|k|ə}} or {{IPAc-en|ˈ|s|p|iː|k|ə}}<ref name=pronunciation/><ref name=oxford/>
|ra       = {{RA|13|25|11.579}}<ref name="van Leeuwen2007"/>
|dec      = {{DEC|−11|09|40.75}}<ref name="van Leeuwen2007"/>
|appmag_v = +0.97<ref name=ducati/> {{nowrap|(0.97–1.04<ref name=ruban/>)}}
}}
{{Starbox character
|class    = {{nowrap|B1III-IV + B2V<ref name=aaa483_3/>}}
|b-v      = −0.23<ref name=ducati/>
|u-b      = −0.94<ref name=ducati/>
|variable = [[Beta Cephei variable|β Cep]] + [[Rotating ellipsoidal variable|Ellipsoidal]]<ref name=ruban/>
}}
{{Starbox astrometry
| radial_v          = +1.0<ref name=gcsrv53/>
| prop_mo_ra        = {{val|−42.35|0.62}}<ref name="van Leeuwen2007"/>
| prop_mo_dec       = {{val|−30.67|0.37}}<ref name="van Leeuwen2007"/>
| parallax          = 13.06
| p_error           = 0.70
| parallax_footnote = <ref name="van Leeuwen2007"/>
| absmag_v          = −3.55 (−3.5/−1.5)<ref name=mnras151/>
}}
{{Starbox orbit
| reference       = <ref name=Tkachenko2016/>
| axis_unitless   = {{Val|28.20|0.92|u=solar radius}}
| period_unitless = {{Val|4.0145|0.0001|u=d}}
| eccentricity    = {{Val|0.133|0.017}}
| inclination     = {{Val|63.1|2.5}}
| periastron      = {{Val|2454189.4|0.02|fmt=commas}}
| periarg         = {{Val|255.6|12.2}}
}}
{{Starbox detail
|source               = <ref name=Tkachenko2016/>
|component1           = Primary
|age                  =
|metal                =
|mass                 = {{Val|11.43|1.15}}
|radius               = {{Val|7.47|0.54}}
|rotation             =
|rotational_velocity  = {{Val|165.3|4.5}}
|luminosity           = {{Val|20500|5000|4000|fmt=commas}}
|temperature          = {{Val|25300|500|fmt=commas}}
|gravity              = {{Val|3.71|0.10}}
|age_myr              = 12.5
|component2           = Secondary
|mass2                = {{Val|7.21|0.75}}
|radius2              = {{Val|3.74|0.53}}
|rotational_velocity2 = {{Val|58.8|1.5}}
|luminosity2          = {{Val|2300|1200|800|fmt=commas}}
|temperature2         = {{Val|20900|800|fmt=commas}}
|gravity2             = {{Val|4.15|0.15}}
}}
{{Starbox catalog
 | names = {{odlist | name=Spica | name2=Azimech | B=Spica&nbsp;Virginis, α&nbsp;Virginis, Alpha&nbsp;Vir | F=67&nbsp;Virginis | HR=5056 
 | BD=-10°3672 | HD=116658 | GCTP=18144 | FK5=498 | CCDM=13252-1109 | SAO=157923 | HIP=65474 }}<ref name=simbad/>
}}
{{Starbox reference
 | Simbad=alf+Vir
}}
{{Starbox end}}

'''Spica''' is the brightest object in the [[constellation]] of [[Virgo (constellation)|Virgo]] and one of the 20 [[List of brightest stars|brightest stars]] in the [[night sky]]. It has the [[Bayer designation]] '''α Virginis''', which is [[Latinisation of names|Latinised]] to '''Alpha Virginis''' and abbreviated '''Alpha Vir''' or '''α Vir'''. Analysis of its [[parallax]] shows that it is located 250{{±|10}} [[light-year]]s from the [[Sun]].<ref name="van Leeuwen2007"/> It is a [[spectroscopic]] [[binary star]] and [[rotating ellipsoidal variable]]; a system whose two stars are so close together they are egg-shaped rather than spherical, and can only be separated by their [[Electromagnetic spectrum|spectra]]. The primary is a [[blue giant]] and a [[variable star]] of the [[Beta Cephei variable|Beta Cephei type]].

Spica, along with [[Arcturus]] and [[Denebola]]—or [[Regulus]], depending on the source—forms the [[Spring Triangle]] [[Asterism (astronomy)|asterism]], and, by extension, is also part of the [[Great Diamond]] together with the star [[Cor Caroli]].

==Nomenclature==
The star's name is derived from the [[Latin]] ''spīca virginis'' "the virgin's ear of [wheat] grain". It was also anglicized as ''Virgin's Spike''.<ref name=allen/> In 2016, the [[International Astronomical Union]] organized a [[Working Group on Star Names]] (WGSN)<ref name=WGSN/> to catalog and standardize proper names for stars. The WGSN's first bulletin of July 2016<ref name=WGSN1/> included a table of the first two batches of names approved by the WGSN; which included ''Spica'' for this star. It is now so entered in the IAU Catalog of Star Names.<ref name="IAU-CSN"/>

''α Virginis'' ([[Latinisation of names|Latinised]] to ''Alpha Virginis'') is the system's [[Bayer designation]].

In the Sumerian Starlist found in Uruk (Iraq), 3200-1500 BC, Spica (or a group of stars in Virgo) is called absinnu or šer'u 𒀊𒉆, "The Seed-Furrow".<ref>{{cite web |title=AB.SIN2, ABSIN (𒀊𒉆) |url=https://xing.fmi.uni-jena.de/mediawiki/index.php/AB.SIN |website=All Skies Encyclopaedia |publisher=[[IAU Working Group on Star Names]] |access-date=17 October 2025}}</ref>

Other traditional names are ''Azimech'' {{IPAc-en|'|æ|z|I|m|E|k}}, from [[Arabic]] السماك الأعزل ''al-simāk al-ʼaʽzal'' 'the unarmed ''simāk'' (of unknown meaning, cf. [[Eta Boötis]]); ''Alaraph''<!--form should be something like الرف, from root رفَ ''rff'', but I'm not finding a match in the vowels-->, Arabic for 'the grape-gatherer' or 'gleaner', and ''Sumbalet'' (''Sombalet'', ''Sembalet'' and variants), from Arabic سنبلة ''sunbulah'' "ear of grain".<ref name=allen/>

In [[Chinese astronomy|Chinese]], {{lang|zh|角宿}} ({{lang|zh-Latn|Jué Xiù}}), meaning ''[[Horn (Chinese constellation)|Horn]] (asterism)'', refers to an asterism consisting of Spica and [[ζ Virginis]].<ref name=zh/> Consequently, the [[Chinese star names|Chinese name]] for Spica is {{lang|zh|角宿一}} ({{lang|zh-Latn|Jué Xiù Yī}}, {{langx|en|the First Star of Horn}}).<ref name=aeea/>

In [[Hindu astronomy]], Spica corresponds to the [[Nakshatra]] ''Chitrā''.<ref>{{cite web |title=Citrā (चित्रा) |url=https://xing.fmi.uni-jena.de/mediawiki/index.php/Chitra |website=All Skies Encyclopaedia |publisher=[[IAU Working Group on Star Names]] |access-date=17 October 2025}}</ref>

==Observational history==
[[File:VirgoCC.jpg|thumb|left|upright|Spica is the brightest star in the constellation of Virgo (lower left).]]

As one of the nearest massive binary star systems to the Sun, Spica has been the subject of many observational studies.<ref name=bass33/>

Spica is believed to be the star that gave [[Hipparchus]] the data that led him to discover the [[Axial precession|precession of the equinoxes]].<ref name=evans98/> A [[temple]] to [[Menat]] (an early [[Hathor]]) at [[Thebes, Egypt|Thebes]] was oriented with reference to Spica when it was built in 3200 BC, and, over time, precession slowly but noticeably changed Spica's location relative to the temple.<ref name=allen03/> [[Nicolaus Copernicus]] made many observations of Spica with his home-made [[triquetrum (astronomy)|triquetrum]] for his researches on precession.<ref name=jrasc37_4/><ref name=moesgaard73/>

== Observation ==
[[Image:Finding spica.png|thumb|How to locate Spica|alt=|left]]

Spica is 2.06 degrees from the [[ecliptic]]{{citation needed|date=January 2021}} and can be [[occultation|occulted]] by the [[Moon]] and sometimes by [[planet]]s. The last planetary occultation of Spica occurred when [[Venus]] passed in front of the star (as seen from [[Earth]]) on November 10, 1783. The next occultation will occur on September 2, 2197, when Venus again passes in front of Spica.<ref name=tonight/> The Sun passes a little more than 2° [[conjunction (astronomy)|north of]] Spica around October 16 every year, and the star's [[heliacal rising]] occurs about two weeks later. Every 8 years, Venus passes Spica around the time of the star's heliacal rising, as in 2009 when it passed 3.5° north of the star on November 3.<ref name=breit10/>

A method of finding Spica is to follow the arc of the handle of the [[Big Dipper]] (or Plough) to Arcturus, and then continue on the same [[angular distance]] to Spica. This can be recalled by the mnemonic phrase, "arc to Arcturus and spike to Spica."<ref name=rao/><ref name=news/>

Stars that can set (not in a [[circumpolar constellation]] for the viewer) culminate at midnight—noticeable where viewed away from any polar region experiencing [[midnight sun]]—when at [[opposition (astronomy)|opposition]], meaning they can be viewed from dusk until dawn. This applies to α Virginis on 12 April, in the current [[astronomical epoch]].<ref name=InTheSky/>

==Physical properties==
[[File:Main_Sequence_Stars_Comparison.jpg|thumb|283x283px|Size comparison of main sequence stars and Spica, including [[Proxima Centauri]], the [[Sun]], and [[Sirius]]]]
Spica is a close [[binary star]] whose components orbit each other every four days. They stay close enough together that they cannot be resolved as two stars through a [[telescope]]. The changes in the orbital motion of this pair results in a [[Doppler shift]] in the [[absorption line]]s of their respective [[stellar spectrum|spectra]], making them a double-lined spectroscopic binary.<ref name=apj704_1/> Initially, the orbital parameters for this system were inferred using spectroscopic measurements. Between 1966 and 1970, the [[Narrabri Stellar Intensity Interferometer]] was used to observe the pair and to directly measure the orbital characteristics and the angular diameter of the primary, which was found to be {{nowrap|(0.90 ± 0.04) × 10<sup>−3</sup> arcseconds}}, and the angular size of the [[semi-major axis]] of the orbit was found to be only slightly larger at {{nowrap|(1.54 ± 0.05) × 10<sup>−3</sup> arcseconds}}.<ref name=mnras151/>

Spica is a [[rotating ellipsoidal variable]], which is a non-eclipsing close binary star system where the stars are mutually distorted through their gravitational interaction. This effect causes the [[apparent magnitude]] of the star system to vary by 0.03 over an interval that matches the orbital period. This slight dip in magnitude is barely noticeable visually.<ref name="apj295"/> Both stars rotate faster than their mutual orbital period. This lack of synchronization and the high ellipticity of their orbit may indicate that this is a young star system. Over time, the mutual tidal interaction of the pair may lead to rotational synchronization and [[tidal circularization|orbit circularization]].<ref name="aass125_1"/>

[[File:AlphaVirLightCurve.png|thumb|left|upright=1.2|A [[light curve]] for Spica, adapted from Tkachenko ''et al.'' (2016)<ref name=Tkachenko2016/>]]
Spica is a polarimetric variable, first discovered to be such in 2016.<ref name="cotton16"/> The majority of the polarimetric signal is the result of the reflection of the light from one star off the other (and vice versa). The two stars in Spica were the first ever to have their reflectivity (or [[geometric albedo]]) measured. The geometric albedos of Spica A and B are, respectively, 3.61 percent and 1.36 percent,<ref name=Bailey2019/> values that are low compared to planets.

The MK [[spectral classification]] of Spica is typically considered to be an early [[B-type star|B-type]] main-sequence star.<ref name="johnson"/> Individual spectral types for the two components are difficult to assign accurately, especially for the secondary due to the [[Struve–Sahade effect]]. The [[Bright Star Catalogue]] listed a spectral class of B1III-IV for the primary and B2V for the secondary,<ref name="bsc"/> but later studies have given various different values.<ref name="popper"/><ref name="odell"/>

The primary star has a [[stellar classification]] of B1III-IV.<ref name=aaa483_3/> The [[luminosity class]] matches the spectrum of a star that is midway between a [[subgiant]] and a [[giant star]], and it is no longer a [[main-sequence star]]. The evolutionary stage has been calculated to be near or slightly past the end of the main-sequence phase.<ref name=odell/> This is a massive star with more than 10 times the [[mass of the Sun]] and seven times [[Solar radius|its radius]]. The [[bolometric luminosity]] of the primary is about 20,500 times that of the [[Sun]], and nine times the luminosity of its companion.<ref name=Tkachenko2016/> The primary is one of the nearest stars to the Sun that has enough mass to end its life in a [[Type II supernova]] explosion.<ref name=kaler/><ref name=Firestone2014/> Since Spica has only recently left the main sequence, this event is not likely to occur for several more million years.

The primary is classified as a [[Beta Cephei variable|Beta Cephei]] [[variable star]] that varies in brightness over a 0.1738-day period. The spectrum shows a [[radial velocity]] variation with the same period, indicating that the surface of the star is regularly pulsating outward and then contracting. This star is rotating rapidly, with a rotational velocity of 199&nbsp;km/s along the [[equator]].<ref name=apj704_1/>

The secondary member of this system is one of the few stars whose spectrum is affected by the Struve–Sahade effect. This is an anomalous change in the strength of the [[spectral line]]s over the course of an orbit, where the lines become weaker as the star is moving away from the observer.<ref name=bass33/> It may be caused by a strong [[stellar wind]] from the primary scattering the light from secondary when it is receding.<ref name=apj479/> This star is smaller than the primary, with about 4 times the mass of the Sun and 3.6 times the Sun's radius.<ref name=apj704_1/> Its stellar classification is B4-7&nbsp;V, making this a [[main-sequence star]].<ref name=aaa483_3/>

==In culture==
Both a rocket and crew capsule designed and under development by [[Copenhagen Suborbitals]], a crowd-funded space program, is named Spica. Spica aims to make Denmark the first country to launch its own [[astronaut]] to space after Russia, the US and China.<ref name=copenhagensuborbitals/>

Spica is one of the [[Behenian fixed star]]s. In his ''[[Three Books of Occult Philosophy]]'', [[Cornelius Agrippa]] attributes Spica's [[kabbalistic]] symbol [[Image:Agrippa1531 Spica.png]] to [[Hermes Trismegistus]].{{cn|date=February 2023}}.
{{Clear}}

==See also==
* [[Lists of astronomical objects]]

==References==
{{Reflist|refs=

<ref name=copenhagensuborbitals>{{Cite web|title=Spica Capsule|url=https://copenhagensuborbitals.com/missions/spica-capsule|access-date=10 April 2021|website=Copenhagen Suborbitals}}</ref>

<ref name=Bailey2019>{{cite journal |last1=Bailey |first1=Jeremy | last2=Cotton | first2=Daniel V. |last3=Kedziora-Chudczer |first3=Lucyna |last4=De Horta |first4=Ain |last5=Maybour |first5=Darren |title=Polarized reflected light from the Spica binary system |journal=Nature Astronomy |date=2019-04-01 |volume=3 |issue=7 |pages=636–641 |doi=10.1038/s41550-019-0738-7 |arxiv=1904.01195 |bibcode=2019NatAs...3..636B |s2cid=131977662 }}</ref>

<ref name=InTheSky>[https://in-the-sky.org/ephemeris.php?ird=1&irs=1&objtype=0&objpl=Mercury&objtxt=Spica&tz=0&startday=15&startmonth=3&startyear=2020&interval=1&rows=100] Ephemeris table. In-the-Sky.org. Dominic C. Ford, 2011–2020; Cambridge
 UK.</ref>

<ref name=gcsrv53>{{cite journal | last=Wilson | first=Ralph Elmer | date=1953 | title=General Catalogue of Stellar Radial Velocities | journal=Carnegie Institute Washington D.C. Publication | publisher=Carnegie Institution of Washington | location=Washington | bibcode=1953GCRV..C......0W }}</ref>

<ref name=Tkachenko2016>{{cite journal | title=Stellar modelling of Spica, a high-mass spectroscopic binary with a β Cep variable primary component | display-authors=1 | last1=Tkachenko | first1=A. | last2=Matthews | first2=J. M. | last3=Aerts | first3=C. | last4=Pavlovski | first4=K. | last5=Pápics | first5=P. I. | last6=Zwintz | first6=K. | last7=Cameron | first7=C. | last8=Walker | first8=G. A. H. | last9=Kuschnig | first9=R. | last10=Degroote | first10=P. | last11=Debosscher | first11=J. | last12=Moravveji | first12=E. | last13=Kolbas | first13=V. | last14=Guenther | first14=D. B. | last15=Moffat | first15=A. F. J. | last16=Rowe | first16=J. F. | last17=Rucinski | first17=S. M. | last18=Sasselov | first18=D. | last19=Weiss | first19=W. W. | journal=Monthly Notices of the Royal Astronomical Society | volume=458 | issue=2 | pages=1964–1976 | date=May 2016 | doi=10.1093/mnras/stw255 | doi-access=free | bibcode=2016MNRAS.458.1964T | arxiv=1601.08069| s2cid=26945389 }}</ref>

<ref name=simbad>{{cite web | title=V* alf Vir -- Variable Star of beta Cep type | work=[[SIMBAD]] | publisher=Centre de Données astronomiques de Strasbourg | url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=alf+Vir | access-date=2010-04-13 }}</ref>

<ref name=evans98>{{cite book | last=Evans | first=James | title=The History and Practice of Ancient Astronomy | publisher=[[Oxford University Press]] | date=1998 | page=259 | isbn=978-0-19-509539-5 }}</ref>

<ref name=allen03>{{cite book | last=Allen | first=Richard Hinckley | title=Star Names and Their Meanings | publisher=[[Kessinger Publishing]] | date=2003 | page=468 | isbn=978-0-7661-4028-8}}</ref>

<ref name=jrasc37_4>{{cite journal | last=Rufus | first=W. Carl | title=Copernicus, Polish Astronomer, 1473–1543 | journal=[[Journal of the Royal Astronomical Society of Canada]] | volume=37 | issue=4 | page=134 |date=April 1943 | bibcode=1943JRASC..37..129R }}</ref>

<ref name=moesgaard73>{{cite conference | first=Kristian P. | last=Moesgaard | title=Copernican influence on Tycho Brahe | editor=Jerzy Dobrzycki | book-title=The reception of Copernicus' heliocentric theory: proceedings of a symposium organized by the Nicolas Copernicus Committee of the International Union of the History and Philosophy of Science | location=Toruń, Poland | date=1973 | publisher=Studia Copernicana, Springer | isbn=90-277-0311-6 | url=https://books.google.com/books?id=tAWp34_GYLAC&q=copernicus+spica&pg=PA35 }}</ref>

<ref name=breit10>{{cite web | first=Derek C. | last=Breit | date=March 12, 2010 | title=Diary of Astronomical Phenomena 2010 | work=Poyntsource.com | url=http://www.poyntsource.com/New/Diary.htm | access-date=2010-04-13 }}</ref>

<ref name=apj704_1>{{cite journal | author=Harrington, David| author2=Koenigsberger, Gloria |author2-link=Gloria Suzanne Koenigsberger Horowitz | author3=Moreno, Edmundo| author4=Kuhn, Jeffrey | title=Line-profile Variability from Tidal Flows in Alpha Virginis (Spica) | journal=The Astrophysical Journal | volume=704 | issue=1 | pages=813–830 |date=October 2009 | doi=10.1088/0004-637X/704/1/813 | bibcode=2009ApJ...704..813H |arxiv = 0908.3336 | s2cid=17955730 }}</ref>

<ref name=mnras151>{{cite journal | title=A study of alpha Virginis with an intensity interferometer | author=Herbison-Evans, D. | author2=Hanbury Brown, R. | author3=Davis, J. | author4=Allen, L. R. | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=151 | issue=2 | pages=161–176 | date=1971 | bibcode=1971MNRAS.151..161H | doi=10.1093/mnras/151.2.161| doi-access=free }}</ref>

<ref name=bass33>{{cite journal | title=Spectroscopy of the temporal variations of α Vir | author=Riddle, R. L. | author2=Bagnuolo, W. G. | author3=Gies, D. R. | journal=[[Bulletin of the American Astronomical Society]] | volume=33 | page=1312 |date=December 2001 | bibcode=2001AAS...199.0613R }}</ref>

<ref name=aass125_1>{{cite journal | last=Beech | first=M. | title=The ellipsoidal variables. III - Circularization and synchronization | journal=[[Astrophysics and Space Science]] | volume=125 | issue=1 | pages=69–75 |date=August 1986 | doi=10.1007/BF00643972 | bibcode=1986Ap&SS.125...69B | s2cid=125499856 }}</ref>

<ref name=apj295>{{cite journal | title=The ellipsoidal variable stars | last=Morris | first=S. L. | journal=Astrophysical Journal, Part 1 | volume=295 | pages=143–152 |date=August 1985 | doi=10.1086/163359 | bibcode=1985ApJ...295..143M }}</ref>

<ref name=apj479>{{cite journal | author=Gies, Douglas R.|last2=Bagnuolo |first2=William G. Jr.| author3=Penny, Laura R. | title=Photospheric Heating in Colliding-Wind Binaries | journal=Astrophysical Journal | volume=479 |issue=1 | page=408 |date=April 1997 | doi=10.1086/303848 | bibcode=1997ApJ...479..408G | doi-access=free }}</ref>

<ref name=kaler>{{cite web | first=Jim | last=Kaler | title=Spica | work=Stars | url=http://stars.astro.illinois.edu/sow/spica.html | access-date=2010-04-15 }}</ref>

<ref name=aaa483_3>{{cite journal | author=Schnerr, R. S. |display-authors=etal | title=Magnetic field measurements and wind-line variability of OB-type stars | journal=Astronomy and Astrophysics | volume=483 | issue=3 | pages=857–867 |date=June 2008 | doi=10.1051/0004-6361:20077740 | bibcode=2008A&A...483..857S |arxiv = 1008.4260 |s2cid=53454915 }}</ref>

<ref name="van Leeuwen2007">{{cite journal | title=Validation of the new Hipparcos reduction | last1=van Leeuwen | first1=F. | journal=Astronomy and Astrophysics | volume=474 | issue=2 | pages=653–664 | date=2007 | arxiv=0708.1752 | bibcode=2007A&A...474..653V | doi=10.1051/0004-6361:20078357 | s2cid=18759600 }} [http://webviz.u-strasbg.fr/viz-bin/VizieR-5?-out.add=.&-source=I/311/hip2&recno=65254 Vizier catalog entry ]</ref>

<ref name=cotton16>{{cite journal | title=The linear polarization of Southern bright stars measured at the parts-per-million level | last=Cotton | first=D. V. |  display-authors=etal | journal=Monthly Notices of the Royal Astronomical Society | volume=455 | issue=2 | pages=1607–1628 |date=January 2016 | bibcode=2016MNRAS.455.1607C
 |doi=10.1093/mnras/stv2185 | doi-access=free |arxiv= 1509.07221 | s2cid=11191040 }}</ref>

<ref name=Firestone2014>{{cite journal
 | title=Observation of 23 Supernovae That Exploded <300 pc from Earth during the past 300 kyr
 | last1=Firestone | first1=R. B.
 | journal=The Astrophysical Journal
 | volume=789 | issue=1 | id=29 | pages=11 | date=July 2014
 | doi=10.1088/0004-637X/789/1/29 | bibcode=2014ApJ...789...29F | url=https://zenodo.org/record/895414| doi-access=free }}</ref>

<ref name=pronunciation>{{cite web|url=https://forvo.com/word/spica/|title=How to pronounce Spica|access-date=2017-02-19}}</ref>

<ref name=oxford>{{cite web|url=https://en.oxforddictionaries.com/definition/Spica|archive-url=https://web.archive.org/web/20160929121145/https://en.oxforddictionaries.com/definition/spica|url-status=dead|archive-date=September 29, 2016|title=Main definitions of spica in English|publisher = Oxford Dictionaries |access-date=2018-02-19}}</ref>

<ref name=ducati>{{cite journal|bibcode=2002yCat.2237....0D|title=VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system|journal=CDS/ADC Collection of Electronic Catalogues|volume=2237|page=0|last1=Ducati|first1=J. R.|date=2002}}</ref>

<ref name=ruban>{{cite journal|bibcode=2006AstL...32..604R|title=Spectrophotometric observations of variable stars|journal=Astronomy Letters|volume=32|issue=9|page=604|last1=Ruban|first1=E. V.|last2=Alekseeva|first2=G. A.|last3=Arkharov|first3=A. A.|last4=Hagen-Thorn|first4=E. I.|last5=Galkin|first5=V. D.|last6=Nikanorova|first6=I. N.|last7=Novikov|first7=V. V.|last8=Pakhomov|first8=V. P.|last9=Puzakova|first9=T. Yu.|year=2006|doi=10.1134/S1063773706090052|s2cid=121747360}}</ref>

<ref name=tonight>{{cite web|url=http://www.berthoudrecorder.com/2010/03/25/earthsky-tonight-%E2%80%94-march-26-2010-moon-swings-close-to-regulus/ |title=Earth-Sky Tonight, March 26, 2010 |archive-url=https://web.archive.org/web/20110707230504/http://www.berthoudrecorder.com/2010/03/25/earthsky-tonight-%E2%80%94-march-26-2010-moon-swings-close-to-regulus/ |archive-date=July 7, 2011 |access-date=2018-08-15}}</ref>

<ref name=rao>{{cite news |last1=Rao |first1=Joe |title=Arc to Arcturus, Speed on to Spica |url=https://www.space.com/3953-arc-arcturus-speed-spica.html |access-date=14 August 2018 |work=Space.com |date=June 15, 2007}}</ref>

<ref name=news>{{cite news |title=Follow the arc to Arcturus, and drive a spike to Spica {{!}} EarthSky.org |url=http://earthsky.org/tonight/follow-the-arc-to-arcturus |access-date=14 August 2018 |work=earthsky.org |date=April 8, 2018}}</ref>

<ref name=allen>{{cite web|url=https://penelope.uchicago.edu/Thayer/E/Gazetteer/Topics/astronomy/_Texts/secondary/ALLSTA/Virgo*.html |title=Star Names - Their Lore and Meaning |author=Richard Hinckley Allen |access-date=2018-08-15}}</ref>

<ref name=WGSN>{{cite web | url=https://www.iau.org/science/scientific_bodies/working_groups/280/ | title=IAU Working Group on Star Names (WGSN)|access-date=22 May 2016}}</ref>

<ref name=WGSN1>{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/WGSN_bulletin1.pdf | title=Bulletin of the IAU Working Group on Star Names, No. 1 |access-date=28 July 2016}}</ref>

<ref name="IAU-CSN">{{cite web | url=http://www.pas.rochester.edu/~emamajek/WGSN/IAU-CSN.txt | title=IAU Catalog of Star Names |access-date=28 July 2016}}</ref>

<ref name=zh>{{cite book|language=zh|author=陳久金|title=中國星座神話|url=https://books.google.com/books?id=0Vex0rYzdu8C|year=2005|publisher=五南圖書出版股份有限公司|isbn=978-986-7332-25-7}}</ref>

<ref name=aeea>{{cite web |language=zh |url=http://aeea.nmns.edu.tw/2006/0606/ap060627.html |title=AEEA 天文教育資訊網, Activities of Exhibition and Education in Astronomy |publisher=National Museum of Natural Science, Taiwan. |access-date=2018-08-15 |archive-date=2011-05-21 |archive-url=https://web.archive.org/web/20110521233906/http://aeea.nmns.edu.tw/2006/0606/ap060627.html |url-status=dead }}</ref>

<ref name=johnson>{{cite journal|bibcode=1953ApJ...117..313J|title=Fundamental stellar photometry for standards of spectral type on the Revised System of the Yerkes Spectral Atlas|journal=The Astrophysical Journal|volume=117|pages=313|last1=Johnson|first1=H. L|last2=Morgan|first2=W. W|year=1953|doi=10.1086/145697}}</ref>

<ref name=bsc>{{cite journal |bibcode=1995yCat.5050....0H |title=VizieR Online Data Catalog: Bright Star Catalogue, 5th Revised ed. (Hoffleit+, 1991) |last1=Hoffleit |first1=D. |author2=Warren, W. H., Jr. |journal=Vizier Online Data Catalog |date=1995 }}</ref>

<ref name=popper>{{cite journal|doi=10.1146/annurev.aa.18.090180.000555|bibcode=1980ARA&A..18..115P|title=Stellar Masses|journal=Annual Review of Astronomy and Astrophysics|volume=18|pages=115–164|year=1980|last1=Popper|first1=Daniel M}}</ref>

<ref name=odell>{{cite journal|doi=10.1086/157771|bibcode=1980ApJ...236..536O|title=The structure of Alpha Virginis. III - the pulsation characteristics|journal=The Astrophysical Journal|volume=236|pages=536|year=1980|last1=Odell|first1=A. P|doi-access=free}}</ref>

}}

{{Virgo}}
{{Portal bar|Astronomy|Stars|Outer space}}
{{Authority control}}
{{Sky|13|25|11.5793|-|11|09|40.759}}

{{DEFAULTSORT:Spica}}
<!-- Properties -->
[[Category:B-type main-sequence stars]]
[[Category:B-type subgiants]]
[[Category:B-type giants]]
[[Category:Beta Cephei variables]]
[[Category:Binary stars]]
[[Category:Rotating ellipsoidal variables]]
<!-- Position/catalogues -->
[[Category:Virgo (constellation)]]
[[Category:Bayer objects|Virginis, Alpha]]
[[Category:Bright Star Catalogue objects|5056]]
[[Category:Durchmusterung objects]]
[[Category:Flamsteed objects|Virginis, 067]]
[[Category:Henry Draper Catalogue objects|116658]]
[[Category:Hipparcos objects|065474]]
[[Category:Stars with proper names]]
[[Category:Lucidae]]