Editing Tucana

{{short description|Constellation in the southern celestial hemisphere}}
{{other uses}}
{{featured article}}
{{Infobox constellation
| name = Tucana
| abbreviation = Tuc<ref name=pa30_469/>
| genitive = Tucanae
| pronounce = {{IPAc-en|tj|uː|ˈ|k|eɪ|n|ə}},<br />genitive {{IPAc-en|-|n|i}}
| symbolism = the [[toucan]]
| RA = {{RA|22|08.45}} to {{RA|01|24.82}}<ref name=boundary/>
| dec= −56.31° to −75.35°<ref name=boundary/>
| family = [[Bayer Family|Bayer]]
| quadrant = SQ1
| areatotal = 295
| arearank = 48th
| numbermainstars = 3
| numberbfstars = 17
| numberstarsplanets = 5
| numberbrightstars = 1
| numbernearbystars = 2<ref name="nearest" group="note">These are [[Zeta Tucanae]] and [[LHS 1208]].</ref>
| brighteststarname = [[Alpha Tucanae|α Tuc]]
| starmagnitude = 2.87
| neareststarname = [[LHS 1208]]
| stardistancely = 26.55
| stardistancepc = 8.14
| numbermessierobjects = 0
| meteorshowers =
| bordering = [[Grus (constellation)|Grus]]<br />[[Indus (constellation)|Indus]]<br />[[Octans]]<br />[[Hydrus]]<br />[[Eridanus (constellation)|Eridanus]] (corner)<br />[[Phoenix (constellation)|Phoenix]]
| latmax = [[25th parallel north|25]]
| latmin = [[South Pole|90]]
| month = October
| notes=
}}

'''Tucana''' (The Toucan) is a [[constellation]] in the [[southern sky]], named after the [[toucan]], a [[South America]]n [[bird]]. It is one of twelve constellations conceived in the late sixteenth century by [[Petrus Plancius]] from the observations of [[Pieter Dirkszoon Keyser]] and [[Frederick de Houtman]]. Tucana first appeared on a {{convert|35|cm|in|adj=mid|-diameter}} [[celestial globe]] published in 1598 in Amsterdam by Plancius and [[Jodocus Hondius]] and was depicted in [[Johann Bayer]]'s star atlas ''[[Uranometria]]'' of 1603. French explorer and astronomer [[Nicolas Louis de Lacaille]] gave its stars [[Bayer designation]]s in 1756. The constellations Tucana, [[Grus (constellation)|Grus]], [[Phoenix (constellation)|Phoenix]] and [[Pavo (constellation)|Pavo]] are collectively known as the "Southern Birds".

Tucana is not a prominent constellation as all of [[List of stars in Tucana|its stars]] are third magnitude or fainter; the brightest is [[Alpha Tucanae]] with an [[apparent magnitude|apparent visual magnitude]] of 2.87. [[Beta Tucanae]] is a star system with six member stars, while [[Kappa Tucanae|Kappa]] is a quadruple system. The constellation contains [[47 Tucanae]], one of the brightest [[globular cluster]]s in the sky, and most of the [[Small Magellanic Cloud]].

==History==

[[File:Johann Bayer - Uraniometria - Southern Birds.jpg|The "southern birds" as seen in [[Johann Bayer]]'s ''[[Uranometria]]''. Tucana (as "Toucan") is in the middle.|thumb|left]]
Tucana is one of the twelve constellations established by the astronomer [[Petrus Plancius]] from the observations of the southern sky by the Dutch explorers [[Pieter Dirkszoon Keyser]] and [[Frederick de Houtman]], who had sailed on the first Dutch trading expedition, known as the ''[[First Dutch Expedition to Indonesia|Eerste Schipvaart]]'', to the [[East Indies]]. It first appeared on a {{convert|35|cm|in|adj=mid|-diameter}} celestial globe published in 1598 in Amsterdam by Plancius with [[Jodocus Hondius]]. The first depiction of this constellation in a [[celestial atlas]] was in the German cartographer [[Johann Bayer]]'s ''[[Uranometria]]'' of 1603. Both Plancius and Bayer depict it as a [[toucan]].<ref>{{cite web| url=http://www.ianridpath.com/startales/bayer-southern.html | title=Bayer's Southern Star Chart|work=Star Tales|last1=Ridpath|first1=Ian|author-link=Ian Ridpath|publisher=self-published | access-date= 18 September 2020}}</ref><!-- cites previous three sentences --><ref name=jasc45_215/> De Houtman included it in his southern star catalogue the same year under the Dutch name ''Den Indiaenschen Exster, op Indies Lang ghenaemt'' "the Indian magpie, named Lang in the Indies",<ref>{{cite web| url=http://www.ianridpath.com/startales/startales1c.html#houtman | title=Frederick de Houtman's Catalogue|last1=Ridpath|first1=Ian|publisher=self-published|work=Star Tales | access-date= 19 October 2013}}</ref> by this meaning a particular bird with a long beak—a [[hornbill]], a bird native to the [[East Indies]]. A 1603 celestial globe by [[Willem Blaeu]] depicts it with a [[wikt:casque|casque]].<ref name="ridpathpav">{{cite web| url=http://www.ianridpath.com/startales/tucana.html|work=Star Tales | title=Tucana– the Toucan |last1=Ridpath|first1=Ian|publisher=self-published | access-date= 19 October 2013}}</ref> It was interpreted on Chinese charts as ''[[Tucana in Chinese astronomy|Niǎohuì]]'' "bird's beak", and in England as "Brasilian Pye", while [[Johannes Kepler]] and [[Giovanni Battista Riccioli]] termed it ''Anser Americanus'' "American Goose", and Caesius as ''Pica Indica''.<ref name="allen">{{cite book | author=Allen, Richard Hinckley | date=1963 | orig-year=1899 | title=Star Names: Their Lore and Meaning | edition=[[Reprint]] | publisher=[[Dover Publications]] Inc. | location=[[New York City|New York]], [[New York (state)|NY]] | url=https://archive.org/details/starnamestheirlo00alle/page/417 | isbn=((0-486-21079-0)) | pages=[https://archive.org/details/starnamestheirlo00alle/page/417 417–18] | url-access=registration | author-link=Richard Hinckley Allen }}</ref> Tucana and the nearby constellations [[Phoenix (constellation)|Phoenix]], [[Grus (constellation)|Grus]] and [[Pavo (constellation)|Pavo]] are collectively called the "Southern Birds".<ref name="binocs">{{cite book|last=Moore|first=Patrick|author-link=Patrick Moore|title=Exploring the Night Sky with Binoculars|publisher=Cambridge University Press|location=Cambridge, United Kingdom |date=2000|page=[https://archive.org/details/exploringnightsk00moor/page/48 48]|isbn=978-0-521-79390-2|url=https://archive.org/details/exploringnightsk00moor|url-access=registration}}</ref>

==Characteristics==
[[File:Constellation Tucana.jpg|thumb|left|The constellation of Tucana, the toucan, as it can be seen by the naked eye]]
Irregular in shape, Tucana is bordered by [[Hydrus]] to the east, Grus and Phoenix to the north, [[Indus (constellation)|Indus]] to the west and [[Octans]] to the south. Covering 295 square degrees, it ranks 48th of the 88 constellations in size. The recommended three-letter abbreviation for the constellation, as adopted by the [[International Astronomical Union]] in 1922, is "Tuc".<ref name=pa30_469/> The official constellation boundaries, as set by Belgian astronomer [[Eugène Joseph Delporte|Eugène Delporte]] in 1930, are defined by a polygon of 10 segments. In the [[equatorial coordinate system]], the [[right ascension]] coordinates of these borders lie between {{RA|22|08.45}} and {{RA|01|24.82}}, while the [[declination]] coordinates are between −56.31° and −75.35°.<ref name=boundary/> As one of the deep southern constellations, it remains below the horizon at latitudes north of the [[30th parallel north|30th parallel]] in the [[Northern Hemisphere]], and is [[Circumpolar star|circumpolar]] at latitudes south of the [[50th parallel south|50th parallel]] in the [[Southern Hemisphere]].<ref name="motz">{{cite book|last=Motz|first=Lloyd|author2=Nathanson, Carol |title=The Constellations: An Enthusiast's Guide to the Night Sky|publisher=Aurum Press|location=London, United Kingdom|date=1991|pages=385, 389|isbn=978-1-85410-088-7}}</ref>

==Features==

===Stars===
{{further|List of stars in Tucana}}
[[File:Sidekick or star of the show?.jpg|left|thumb|Sidekick or star of the show?<ref>{{cite web|title=Sidekick or star of the show?|url=https://www.spacetelescope.org/images/potw1707a/|website=www.spacetelescope.org|access-date=14 February 2017}}</ref>]]
Although he depicted Tucana on his chart, Bayer did not assign its stars [[Bayer designation]]s. French explorer and astronomer [[Nicolas Louis de Lacaille]] labelled them Alpha to Rho in 1756, but omitted Omicron and Xi, and labelled a pair of stars close together Lambda Tucanae, and a group of three stars Beta Tucanae. In 1879, American astronomer [[Benjamin Apthorp Gould|Benjamin Gould]] designated a star Xi Tucanae—this had not been given a designation by Lacaille who had recognized it as nebulous, and it is now known as the globular cluster 47 Tucanae. Mu Tucanae was dropped by [[Francis Baily]], who felt the star was too faint to warrant a designation, and Kappa's two components came to be known as Kappa<sup>1</sup> and Kappa<sup>2</sup>.<ref name="wagman">{{cite book | last = Wagman | first = Morton | date = 2003 | title = Lost Stars: Lost, Missing and Troublesome Stars from the Catalogues of Johannes Bayer, Nicholas Louis de Lacaille, John Flamsteed, and Sundry Others | publisher = The McDonald & Woodward Publishing Company | location = Blacksburg, [[Virginia|VA]] | isbn = 978-0-939923-78-6 |pages=305–07}}</ref><!-- cites previous three sentences -->

The layout of the brighter stars of Tucana has been likened to a kite.<ref name="striecher 2005">{{cite journal|last=Streicher|first=Magda|date=2005|title=Deepsky Delights|journal=Monthly Notes of the Astronomical Society of Southern Africa|volume=64|issue=9–10|pages=172–74|bibcode=2005MNSSA..64..172S}}</ref> Within the constellation's boundaries are around 80 stars brighter than an apparent magnitude of 7.<ref name="o'meara">{{cite book |title=Deep-Sky Companions: Southern Gems |first=Stephen James |last=O'Meara |publisher=Cambridge University Press|location=Cambridge, United Kingdom |date=2013 |pages=16–17 |isbn=978-1-107-01501-2|url=https://books.google.com/books?id=S5QIEKns33sC&q=47+Tucanae&pg=PA17}}</ref> At an apparent magnitude of 2.86,<ref name=simbadalpha>{{cite web |url= http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Alpha+Tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Alpha Tucanae |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 19 October 2013}}</ref> [[Alpha Tucanae]] is the brightest star in the constellation and marks the toucan's head.<ref name="motz"/> It is an orange subgiant of [[stellar classification|spectral type]] K3III around 199 [[light-year]]s distant from the [[Solar System]].<ref name=simbadalpha/> A cool star with a surface temperature of 4300 K, it is 424 times as luminous as the Sun and 37 times its diameter. It is 2.5 to 3 times as massive.<ref name="kaleralpha">{{cite web|url=http://stars.astro.illinois.edu/sow/alphatuc.html |title=Alpha Tucanae |last=Kaler|first=Jim|author-link= James B. Kaler |work=Stars|publisher=University of Illinois|access-date=19 October 2013}}</ref> Alpha Tucanae is a [[spectroscopic binary]], which means that the two stars have not been individually resolved using a telescope, but the presence of the companion has been inferred from measuring changes in the [[stellar spectrum|spectrum]] of the primary. The orbital period of the [[binary system]] is 4197.7&nbsp;days (11.5 years).<ref name=ncsbo>{{cite journal | display-authors=6 | author=Pourbaix, D. | author2=Tokovinin, A.A. | author3=Batten, A.H. | author4=Fekel, F.C. | author5=Hartkopf, W.I. | author6=Levato, H. | author7=Morell, N. I. | author8=Torres, G. | author9=Udry, S. | date=2004 | title=SB9: The Ninth Catalogue of Spectroscopic Binary Orbits | journal=Astronomy & Astrophysics | volume=424 | issue=2 | bibcode=2004A&A...424..727P | doi=10.1051/0004-6361:20041213 | pages=727–732| arxiv=astro-ph/0406573 | s2cid=119387088 }}</ref> Nothing is known about the companion.<ref name="kaleralpha"/> Two degrees southeast of Alpha is the red-hued [[Nu Tucanae]],<ref name="motz"/> of spectral type M4III and lying around 290 light-years distant.<ref name=simbadnu>{{cite news |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Nu+tucanae&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Nu Tucanae – Pulsating Variable Star |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 20 October 2013}}</ref> It is classified as a [[semiregular variable star]] and its brightness varies from magnitude +4.75 to +4.93.<ref name=AAVSOnu>{{cite web|url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=37104 |title=Nu Tucanae |author=Watson, Christopher|date=25 August 2009|work=AAVSO Website|publisher=American Association of Variable Star Observers|access-date=2 February 2014}}</ref> Described by Richard Hinckley Allen as bluish,<ref name="allen"/> [[Gamma Tucanae]] is a yellow-white sequence star of spectral type F4V and an apparent magnitude of 4.00 located around 75 light-years from Earth.<ref name=simbadgamma>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Gamma+tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Gamma Tucanae |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 20 October 2013}}</ref> It also marks the toucan's beak.<ref name=knobel>{{cite journal | title = On Frederick de Houtman's Catalogue of Southern Stars, and the Origin of the Southern Constellations | author= Knobel, Edward B. | author-link= Edward Knobel |journal = [[Monthly Notices of the Royal Astronomical Society]] | volume= 77| issue= 5 | pages=414–32 [430] | bibcode = 1917MNRAS..77..414K |date=1917 | doi=10.1093/mnras/77.5.414| doi-access= free }}</ref>

[[Beta Tucanae|Beta]], [[Delta Tucanae|Delta]] and [[Kappa Tucanae|Kappa]] are multiple [[star system]]s containing six, two and four stars respectively. Located near the tail of the toucan,<ref name="motz"/> Beta Tucanae's two brightest components, Beta<sup>1</sup> and Beta<sup>2</sup> are separated by an angle of 27 [[arcsecond]]s and have apparent magnitudes of 4.4 and 4.5 respectively. They can be separated in small telescopes. A third star, Beta<sup>3</sup> Tucanae, is separated by 10 [[arcminute]]s from the two, and able to be seen as a separate star with the unaided eye. Each star is itself a binary star, making six in total.<ref name="turnleft">{{cite book|last=Consolmagno|first=Guy |title=Turn Left at Orion: Hundreds of Night Sky Objects to See in a Home Telescope – and How to Find Them|publisher=Cambridge University Press|location=Cambridge, United Kingdom|date=2011|page=315|isbn=978-1-139-50373-0|url=https://books.google.com/books?id=h3712RgWkOYC&q=%22Kappa+tucanae%22&pg=PA215}}</ref><!-- cites previous three sentences --> Lying in the southwestern corner of the constellation around 251 light-years away from Earth, Delta Tucanae consists of a blue-white primary contrasting with a yellowish companion.<ref name="striecher 2005"/> Delta Tucanae A is a [[main sequence]] star of spectral type B9.5V and an apparent magnitude of 4.49.<ref name=simbaddeltaa>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=delta+tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Delta Tucanae – Star in Double System |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 25 October 2013}}</ref> The companion has an apparent magnitude of 9.3.<ref name=simbaddeltab>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=CCDM%20J22273-6458%20B |title = CPD-65 4044B – Star in Double System |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 25 October 2013}}</ref> The Kappa Tucanae system shines with a combined apparent magnitude of 4.25, and is located around 68 light-years from the Solar System.<ref name=simbadkap>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=kappa+tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Kappa Tucanae – Double or Multiple Star |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 24 October 2013}}</ref> The brighter component is a yellowish star,<ref name="turnleft"/> known as Kappa Tucanae A with an apparent magnitude of 5.33 and spectral type F6V,<ref name=simbadkapa>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%405362607&Name=*%20kap%20Tuc%20A&submit=submit |title = Kappa Tucanae A – Star in Double System |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 24 October 2013}}</ref> while the fainter lies 5 arcseconds to the northwest.<ref name="turnleft"/> Known as Kappa Tucanae B, it has an apparent magnitude of 7.58 and spectral type K1V.<ref name=simbadkapb>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=%403230627&Name=*%20kap%20Tuc%20B&submit=submit |title = Kappa Tucanae B – Star in Double System |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 24 October 2013}}</ref> Five arcminutes to the northwest is a fainter star of apparent magnitude 7.24—actually a pair of orange main sequence stars of spectral types K2V and K3V,<ref name=simbadkapcd>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=GJ%2055.1 |title = GJ 55.1 – Double or multiple star |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 24 October 2013}}</ref> which can be seen individually as stars one arcsecond apart with a telescope such as a [[Dobsonian telescope|Dobsonian]] with high power.<ref name="turnleft"/>
[[File:Small Magellanic Cloud (Digitized Sky Survey 2).jpg|thumb|right|Most of the [[Small Magellanic Cloud]] lies within Tucana.]]

[[Lambda Tucanae]] is an optical double—that is, the name is given to two stars (Lambda<sup>1</sup> and Lambda<sup>2</sup>) which appear close together from the Earth, but are in fact far apart in space. Lambda<sup>1</sup> is itself a binary star, with two components—a yellow-white star of spectral type F7IV-V and an apparent magnitude of 6.22,<ref name=simbadlambda1a>{{cite web |url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=lam1+tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = HR 252 – Star in Double System |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 21 October 2013}}</ref> and a yellow main sequence star of spectral type G1V and an apparent magnitude of 7.28.<ref name=simbadlambda1b>{{cite web |url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=HR+++252&NbIdent=query_hlinks&Coord=00+52+24.52075-69+30+13.5690&submit=siblings&hlinksdisplay=h_all |title = HD 5208 – Star in Double System |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 21 October 2013}}</ref> The system is 186 light-years distant.<ref name=simbadlambda1a/> Lambda<sup>2</sup> is an orange subgiant of spectral type K2III that is expanding and cooling and has left the main sequence. Of apparent magnitude 5.46, it is approximately 220 light-years distant from [[Earth]].<ref name=simbadlambda2>{{cite web |url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=lambda2+tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Lambda 2 Tucanae – Red Giant Branch Star |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 20 October 2013}}</ref>

[[Epsilon Tucanae]] traditionally marks the toucan's left leg.<ref name=knobel/> A B-type [[subgiant]], it has a spectral type B9IV and an apparent magnitude of 4.49. It is approximately 373 light-years from Earth.<ref name=simbadeps>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=eps+tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Epsilon Tucanae – Be Star |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 20 October 2013}}</ref> It is around four times as massive as the Sun.<ref>{{cite journal|author=Levenhagen, R. S.|author2=Leister, N. V.|date=2006|title=Spectroscopic Analysis of Southern B and Be Stars|journal=Monthly Notices of the Royal Astronomical Society|volume=371|issue=1|pages=252–62|arxiv = astro-ph/0606149 |bibcode = 2006MNRAS.371..252L |doi = 10.1111/j.1365-2966.2006.10655.x |doi-access=free |s2cid=16492030}}</ref>

[[Theta Tucanae]] is a white [[stellar classification|A-type]] star around 423 light-years distant from Earth,<ref name=simbadthet>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Nu+tucanae&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Theta Tucanae – Variable Star of Delta Scuti type |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 2 February 2014}}</ref> which is actually a close binary system. The main star is classified as a [[Delta Scuti variable]]—a class of short period (six hours at most) pulsating stars that have been used as [[Cosmic distance ladder#Standard candles|standard candles]] and as subjects to study [[asteroseismology]].<ref>{{cite web|url=http://www.aavso.org/vsots_delsct|title=Delta Scuti and the Delta Scuti Variables|last=Templeton|first=Matthew |date=16 July 2010|work=Variable Star of the Season|publisher=AAVSO (American Association of Variable Star Observers)|access-date=2 February 2014}}</ref> It is around double the Sun's mass, having siphoned off one whole [[solar mass]] from its companion, now a hydrogen-depleted dwarf star of around only 0.2 solar masses.<ref name="templton00">{{cite journal|author=Templeton, Matthew R.|author2=Bradley, Paul A.|author3=Guzik, Joyce A. |date=2000|title=Asteroseismology of the Multiply Periodic Delta Scuti Star Theta Tucanae|journal=The Astrophysical Journal|volume=528|issue=2|pages=979–88|doi=10.1086/308191|bibcode = 2000ApJ...528..979T |doi-access=free}}</ref> The system shines with a combined light that varies between magnitudes 6.06 to 6.15 every 70 to 80 minutes.<ref name=AAVSOthet>{{cite web|url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=37102 |title=Theta Tucanae |author=Watson, Christopher|date=4 January 2010|work=AAVSO Website|publisher=American Association of Variable Star Observers|access-date=2 February 2014}}</ref><ref name="stobie76">{{cite journal|author=Stobie, R. S.|author2=Shobbrook, R. R.|date=1976|title=Frequency Analysis of the Delta Scuti star, Theta Tucanae|journal=Monthly Notices of the Royal Astronomical Society|volume=174|issue=2|pages=401–09|bibcode = 1976MNRAS.174..401S|doi=10.1093/mnras/174.2.401|doi-access=free}}</ref>

[[Zeta Tucanae]] is a yellow-white main sequence star of spectral type F9.5V and an apparent magnitude of 4.20 located 28 light-years away from the Solar System.<ref name=simbadzet>{{cite web |url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=zeta+tuc&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title = Zeta Tucanae  |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 20 October 2013}}</ref> Despite having a slightly lower mass, this star is more luminous than the Sun.<ref name="aaa373">{{cite journal | last1=Santos | first1=N. C. | last2=Israelian | first2=G. | last3=Mayor | first3=M. | title=The metal-rich nature of stars with planets | journal=Astronomy and Astrophysics | volume=373 | issue=3 | pages=1019–1031 |date=July 2001 | doi=10.1051/0004-6361:20010648 | bibcode=2001A&A...373.1019S | arxiv=astro-ph/0105216 | s2cid=119347084 }}</ref> The composition and mass of this star are very similar to the Sun, with a slightly lower mass and an estimated age of three billion years. The solar-like qualities make it a target of interest for investigating the possible existence of a life-bearing planet.<ref name="ab6">{{cite journal | last1=Porto de Mello | first1=Gustavo | last2=del Peloso | first2=Eduardo F. | last3=Ghezzi | first3=Luan | date=2006 | title=Astrobiologically Interesting Stars Within 10 Parsecs of the Sun | journal=Astrobiology | volume=6 | issue=2 | pages=308–331 | doi=10.1089/ast.2006.6.308 | pmid=16689649 | bibcode=2006AsBio...6..308P | arxiv=astro-ph/0511180 | s2cid=119459291 }}</ref> It appears to have a [[debris disk]] orbiting it at a minimum radius of 2.3 [[astronomical unit]]s.<ref name="apj674">{{cite journal | display-authors =6 | author =Trilling, D.E. | author2 =Bryden, G. | author3 =Beichman, C.A. | author4 =Rieke, G.H. | author5 =Su, K.Y.L. | author6 =Stansberry, J.A. | author7 =Blaylock, M. | author8 =Stapelfeldt, K.R. | author9 =Beeman, J.W. | author10 =Haller, E.E. | date=2008 | title=Debris Disks around Sun-like Stars | journal=The Astrophysical Journal | volume=674 | issue=2 | pages=1086–1105 | doi=10.1086/525514 | bibcode=2008ApJ...674.1086T |arxiv = 0710.5498 | s2cid =54940779 }}</ref> As of 2009, no planet has been discovered in orbit around this star.<ref name=apjl700_2>{{cite journal | last1=Kóspál | first1=Ágnes | last2=Ardila | first2=David R. | last3=Moór | first3=Attila | last4=Ábrahám | first4=Péter | title=On the Relationship Between Debris Disks and Planets | journal=The Astrophysical Journal Letters | volume=700 | issue=2 | pages=L73–L77 |date=August 2009 | doi=10.1088/0004-637X/700/2/L73 | bibcode=2009ApJ...700L..73K |arxiv = 0907.0028 | s2cid=16636256 }}</ref>

Five star systems have been found to have planets, four of which have been discovered by the [[High Accuracy Radial Velocity Planet Searcher]] (HARPS) in Chile. [[HD 4308]] is a star with around 83% of the Sun's mass located 72 light-years away with a [[super-Earth]] planet with an orbital period of around 15 days.<ref name="Udry2006">{{cite journal | title=The HARPS Search for Southern Extra-solar Planets V. A 14 Earth-masses planet orbiting HD 4308 | display-authors=6 | author=Udry, S. | author2=Mayor, M. | author3=Benz, W. | author4=Bertaux, J.-L. | author5=Bouchy, F. | author6=Lovis, C. | author7=Mordasini, C. | author8=Pepe, F. | author9=Queloz, D. | author10=Sivan, J.-P. | journal=Astronomy and Astrophysics | volume=447 | issue=1 | pages=361–67 | year=2006 | arxiv=astro-ph/0510354 | bibcode=2006A&A...447..361U | doi=10.1051/0004-6361:20054084 | s2cid=119078261 }}</ref> [[HD 215497]] is an orange star of spectral type K3V around 142 light-years distant. It is orbited by a hot super-Earth every 3 days and a second planet around the size of Saturn with a period of around 567 days.<ref name="Lo Curto2010">{{cite journal | title=The HARPS Search for Southern Extra-solar Planets XXII. Multiple Planet Systems from the HARPS Volume Limited Sample | url=http://www.aanda.org/articles/aa/full_html/2010/04/aa13523-09/aa13523-09.html | display-authors =6 | author =Lo Curto, G. | author2 =Mayor, M. | author3 =Benz, W. | author4 =Bouchy, F. | author5 =Lovis, C. | author6 =Moutou, C. | author7 =Naef, D. | author8 =Pepe, F. | author9 =Queloz, D. | author10 =Santos, N. C. | author11 =Segransan, D. | author12 =Udry, S.| journal=Astronomy and Astrophysics | volume=512 | pages=A48 | year=2015 | bibcode=2010A&A...512A..48L | doi=10.1051/0004-6361/200913523 | arxiv=1411.7048 }}</ref> [[HD 221287]] has a spectral type of F7V and lies 173 light-years away, and has a [[super-Jupiter|super-Jovian]] planet.<ref name="Naef">{{Cite journal | title=The HARPS Search for Southern Extra-solar Planets IX. Exoplanets Orbiting HD 100777, HD 190647, and HD 221287 | display-authors=6 | author=Naef, D. | author2=Mayor, M. | author3=Benz, W. | author4=Bouchy, F. | author5=Lo Curto, G. | author6=Lovis, C. | author7=Moutou, C. | author8=Pepe, F. | author9=Queloz, D. | author10=Santos, N. C. | author11=Udry, S. | journal=[[Astronomy and Astrophysics]] | date=2007 | volume=470 | issue=2 | pages=721–26 | doi=10.1051/0004-6361:20077361 | bibcode=2007A&A...470..721N|arxiv = 0704.0917 | s2cid=119585936 }} ([https://arxiv.org/abs/0704.0917 web preprint])</ref> [[HD 7199]] has spectral type KOIV/V and is located 117 light-years away. It has a planet with around 30% the mass of Jupiter that has an orbital period of 615 days.<ref name=HARPSXXX>{{cite journal |title=The HARPS Search for Southern Extra-solar Planets. XXX. Planetary Systems around Stars with Solar-like Magnetic Cycles and Short-term Activity Variation |display-authors=6 |author=Dumusque, X. |author2=Lovis, C. |author3=Ségransan, D. |author4=Mayor, M. |author5=Udry, S. |author6=Benz, W. |author7=Bouchy, F. |author8=Lo Curto, G. |author9=Mordasini, C. |author10=Pepe, F. |author11=Queloz, D. |author12=Santos, N. C. |author13=Naef, D. |journal=Astronomy & Astrophysics |volume=535 |pages=A55–A66 |doi=10.1051/0004-6361/201117148 |url=http://cds.aanda.org/articles/aa/full_html/2011/11/aa17148-11/aa17148-11.html |arxiv=1107.1748 |bibcode=2011A&A...535A..55D |year=2011 |s2cid=119192207 |access-date=2013-10-26 |archive-url=https://web.archive.org/web/20150529071847/http://cds.aanda.org/articles/aa/full_html/2011/11/aa17148-11/aa17148-11.html |archive-date=2015-05-29 |url-status=dead }}</ref> [[HD 219077]] has a planet around 10 times as massive as Jupiter in a highly eccentric orbit.<ref name=coralie>{{cite journal|title=The CORALIE Survey for Southern Extrasolar Planets XVII. New and Updated Long Period and Massive Planets|journal=Astronomy & Astrophysics|volume=551|pages=A90–A103|arxiv=1211.6444|display-authors=6|author=Marmier, Maxime|author2=Ségransan, D.|author3=Udry, S.|author4=Mayor, M.|author5=Pepe, F.|author6=Queloz, D.|author7=Lovis, C.|author8=Naef, D.|author9=Santos, N. C.|author10=Alonso, R.|author11=Alves, S.|author12=Berthet, S.|author13=Chazelas, B.|author14=Demory, B.-O.|author15=Dumusque, X.|author16=Eggenberger, A.|author17=Figueira, P.|author18=Gillon, M.|author19=Hagelberg, J.|author20=Lendl, M.|author21=Mardling, R. A.|author22=Mégevand, D.|author23=Neveu, M.|author24=Sahlmann, J.|author25=Sosnowska, D.|author26=Tewes, M.|author27=Triaud, A. H. M. J.
|date=2013|doi = 10.1051/0004-6361/201219639 |bibcode = 2013A&A...551A..90M |s2cid=59467665}}</ref>

===Deep-sky objects===
[[File:The Globular Cluster 47 Tu.jpg|thumb|right|alt=Globular Cluster 47 Tucana|Globular Cluster 47 Tuc. Credit [[ESO]]]]
The second-brightest [[globular cluster]] in the sky after [[Omega Centauri]], [[47 Tucanae]] (NGC 104) lies just west of the [[Small Magellanic Cloud]]. Only 14,700 light-years distant from Earth, it is thought to be around 12 billion years old.<ref name="o'meara"/> Mostly composed of old, yellow stars, it does possess a contingent of [[blue stragglers]], hot stars that are hypothesized to form from [[binary star merger]]s.<ref name="objects"/> 47 Tucanae has an apparent magnitude of 3.9, meaning that it is visible to the naked eye; it is a Shapley class III cluster, which means that it has a clearly defined nucleus. Near to 47 Tucana on the sky, and often seen in wide-field photographs showing it, are two much more distant globular clusters associated with the SMC: [[NGC 121]], 10 arcminutes away from the bigger cluster's edge, and [[Lindsay 8]].{{sfn|Levy|2005|pp=163–164}}

[[NGC 362]] is another globular cluster in Tucana with an apparent magnitude of 6.4, 27,700 light-years from Earth. Like neighboring 47 Tucanae, NGC 362 is a Shapley class III cluster and among the brightest globular clusters in the sky. Unusually for a globular cluster, its orbit takes it very close to the center of the Milky Way—approximately 3,000 light-years. It was discovered in the 1820s by [[James Dunlop]].{{sfn|Levy|2005|p=165}} Its stars become visible at 180x magnification through a telescope.<ref name="striecher 2005"/>

[[File:The oldest cluster in its cloud.jpg|thumb|Globular cluster NGC 121<ref>{{cite news|title=The oldest cluster in its cloud|url=http://www.spacetelescope.org/images/potw1428a/|access-date=8 August 2014|work=ESA/Hubble Picture of the Week}}</ref>]]

Located at the southern end of Tucana, the Small Magellanic Cloud is a [[dwarf galaxy]] that is one of the nearest neighbors to the [[Milky Way]] galaxy at a distance of 210,000 light-years. Though it probably formed as a disk shape, [[tidal forces]] from the Milky Way have distorted it. Along with the [[Large Magellanic Cloud]], it lies within the [[Magellanic Stream]], a cloud of gas that connects the two galaxies.<ref name="objects">{{cite book |title = 300 Astronomical Objects: A Visual Reference to the Universe |last1 = Wilkins |first1 = Jamie |last2 = Dunn |first2 = Robert |publisher = Firefly Books |location = Buffalo, New York |date = 2006 |isbn = 978-1-55407-175-3}}</ref> [[NGC 346]] is a star-forming region located in the Small Magellanic Cloud. It has an apparent magnitude of 10.3.<ref name="striecher 2005"/> Within it lies the triple star system [[HD 5980]], each of its members among the most luminous stars known.<ref name=triple>{{Cite journal | last1 = Georgiev | first1 = L. | last2 = Koenigsberger | first2 = G. | last3 = Hillier | first3 = D. J. | last4 = Morrell | first4 = N. | last5 = Barbá | first5 = R. | last6 = Gamen | first6 = R. | doi = 10.1088/0004-6256/142/6/191 | title = Wind Structure and Luminosity Variations in the Wolf-Rayet/luminous Blue Variable Hd 5980 | journal = The Astronomical Journal | volume = 142 | issue = 6 | pages = 191 | year = 2011 |bibcode = 2011AJ....142..191G | doi-access = free | hdl = 11336/9695 | hdl-access = free }}</ref>

[[File:The Toucan and the cluster.jpg|left|thumb|Open star cluster [[NGC 299]] is located within the [[Small Magellanic Cloud]].<ref>{{cite web|title=The Toucan and the cluster|url=https://www.spacetelescope.org/images/potw1642a/|website=www.spacetelescope.org|access-date=17 October 2016}}</ref>]]

The [[Tucana Dwarf]] galaxy, which was discovered in 1990, is a [[dwarf spheroidal galaxy]] of [[Galaxy morphological classification|type dE5]] that is an isolated member of the [[Local Group]].<ref name="LaveryMighell1992">{{Cite journal | doi = 10.1086/116042 | last = Lavery | first = Russell J. |author2=Mighell, Kenneth J.  | title = A New Member of the Local Group – The Tucana Dwarf Galaxy | journal = [[The Astronomical Journal]] | volume = 103 | issue = 1 | pages = 81–84 | date = January 1992 | bibcode = 1992AJ....103...81L}}</ref> It is located {{convert|870|kpc|kly|lk=on}} from the Solar System and around {{convert|1100|kpc|kly}} from the barycentre of the Local Group—the second most remote of all member galaxies after the [[Sagittarius Dwarf Irregular Galaxy]].<ref name="vandenbergh2000">{{ Cite journal | last1 = van den Bergh | first1 = Sidney | author-link1 = Sidney van den Bergh | title = Updated Information on the Local Group | date = 2000 | journal = [[The Publications of the Astronomical Society of the Pacific]] | volume = 112 | issue = 770 | pages = 529–36 | bibcode = 2000PASP..112..529V | doi = 10.1086/316548 |arxiv = astro-ph/0001040 | s2cid = 1805423 }}</ref>

The [[barred spiral galaxy]] [[NGC 7408]] is located 3 degrees northwest of Delta Tucanae, and was initially mistaken for a planetary nebula.<ref name="striecher 2005"/>

In 1998, part of the constellation was the subject of a two-week observation program by the [[Hubble Space Telescope]], which resulted in the [[Hubble Deep Field South]].<ref name=aj120_4_1648/> The potential area to be covered needed to be at the poles of the telescope's orbit for continuous observing, with the final choice resting upon the discovery of a [[quasar]], QSO J2233-606, in the field.<ref>{{cite journal | display-authors = 6 | author = Williams, Robert E. | author2 = Baum, Stefi | author3 = Bergeron, Louis E. | author4 = Bernstein, Nicholas | author5 = Blacker, Brett S. | author6 = Boyle, Brian J. | author7 = Brown, Thomas M. | author8 = Carollo, C. Marcella | author9 = Casertano, Stefano | author10 = Covarrubias, Riccardo | author11 = de Mello, Duília F. | author12 = Dickinson, Mark E. | author13 = Espey, Brian R. | author14 = Ferguson, Henry C.  | author15 = Fruchter, Andrew | author16 = Gardner, Jonathan P. | author17 = Gonnella, Anne | author18 = Hayes, Jeffrey | author19 = Hewett, Paul C. | author20 = Heyer, Inger | author21 = Hook, Richard  | author22 = Irwin, Mike | author23 = Jones, Daniel | author24 = Kaiser, Mary Elizabeth | author25 = Levay, Zolt | author26 = Lubenow, Andy | author27 = Lucas, Ray A. | author28 = Mack, Jennifer | author29 = MacKenty, John W. | author30 = Madau, Piero  | author31 = Makidon, Russell B.; Martin, Crystal L.; Mazzuca, Lisa; Mutchler, Max; Norris, Ray P.; Perriello, Beth; Phillips, M. M.; Postman, Marc; Royle, Patricia; Sahu, Kailash; Savaglio, Sandra; Sherwin, Alison; Smith, T. Ed; Stiavelli, Massimo; Suntzeff, Nicholas B.; Teplitz, Harry I.; van der Marel, Roeland P.; Walker, Alistair R.; Weymann, Ray J.; Wiggs, Michael S.; Williger, Gerard M.; Wilson, Jennifer; Zacharias, Norbert; Zurek, David R. | date = 2000  | title = The Hubble Deep Field South: Formulation of the Observing Campaign  | bibcode =2000AJ....120.2735W  | journal = The Astronomical Journal  | volume = 120  | issue = 6  | pages = 2735–46  | doi = 10.1086/316854 | doi-access = free }}</ref>

== See also ==
* [[Tucana (Chinese astronomy)]]

== Notes ==
{{reflist|group="note"|refs=
}}

==References==
{{reflist|30em|refs=

<ref name=jasc45_215>{{cite journal | last1=Sawyer Hogg | first1=Helen | title=Out of Old Books (Pieter Dircksz Keijser, Delineator of the Southern Constellations) | journal=Journal of the Royal Astronomical Society of Canada | volume=45 | page=215 |date=1951 | bibcode=1951JRASC..45..215S }}</ref>

<ref name=pa30_469>{{cite journal | last1=Russell | first1=Henry Norris | title=The New International Symbols for the Constellations | journal=[[Popular Astronomy (US magazine)|Popular Astronomy]] | volume=30 | pages=469–71 |date=October 1922 | bibcode=1922PA.....30..469R }}</ref>

<ref name=aj120_4_1648>{{cite journal | last1=Cristiani | first1=S. | last2=D'Odorico | first2=V. | title=High-Resolution Spectroscopy from 3050 to 10000 Å of the Hubble Deep Field South QSO J2233-606 with UVES at the ESO Very Large Telescope | journal=The Astronomical Journal | volume=120 | issue=4 | pages=1648–53 |date=2000 | doi=10.1086/301575 | bibcode=2000AJ....120.1648C |arxiv = astro-ph/0006128 | s2cid=117552533 }}</ref>

<ref name=boundary>{{cite web | title=Tucana, constellation boundary | work=The Constellations | publisher=International Astronomical Union | url=http://www.iau.org/public/constellations/#tuc | access-date=1 February 2012 }}</ref>

}}

==Cited texts==
* {{cite book |first = David H. |last = Levy |title = Deep Sky Objects |publisher = Prometheus Books |date = 2005 |isbn = 1-59102-361-0 |url-access = registration |url = https://archive.org/details/deepskyobjects00davi }}

==External links==
{{Commons|Tucana}}
* [http://www.allthesky.com/constellations/tucana/constell.html The Deep Photographic Guide to the Constellations: Tucana]

{{Stars of Tucana}}
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{{DEFAULTSORT:Tucana}}
[[Category:Tucana| ]]
[[Category:Southern constellations]]
[[Category:Legendary birds]]
[[Category:Constellations listed by Petrus Plancius]]