View source for Astronomy:Pavo (constellation)

{{Short description|Constellation in the southern celestial hemisphere}}
{{Infobox constellation
| name = Pavo
| abbreviation = Pav
| genitive = Pavonis
| pronounce = {{IPAc-en|ˈ|p|eɪ|v|oʊ}}, {{IPAc-en|ˈ|p|a:|v|oʊ}},<br />genitive {{IPAc-en|p|ə|ˈ|v|oʊ|n|ᵻ|s}}
| symbolism = the [[Biology:Peafowl|Peacock]]
| RA = {{RA|18|10.4}} to {{RA|21|32.4}}<ref name="boundary"/>
| dec= {{DEC|-56|35.4}} to {{DEC|−74|58.8}}<ref name="boundary"/>
| family = Bayer
| quadrant = SQ4
| areatotal = 378
| arearank = 44th
| numbermainstars = 7
| numberbfstars = 24
| numberstarsplanets = 6
| numberbrightstars = 1
| numbernearbystars = 4
| brighteststarname = [[Astronomy:Alpha Pavonis|α Pav]] (Peacock)
| starmagnitude = 1.91
| numbermessierobjects = 0
| meteorshowers = Delta Pavonids<ref name="deltapavs" />
| bordering = [[Astronomy:Octans|Octans]]<br />[[Astronomy:Apus|Apus]]<br />[[Astronomy:Ara (constellation)|Ara]]<br />[[Astronomy:Telescopium|Telescopium]]<br />[[Astronomy:Indus (constellation)|Indus]]
| latmax = 30
| latmin = [[Earth:South Pole|90]]
| month = August
| notes=
}}

'''Pavo''' is a [[Astronomy:Constellation|constellation]] in the southern sky whose name is [[Social:Latin|Latin]] for {{gloss|[[Biology:Peafowl|peacock]]}}. Pavo first appeared on a 35-cm (14&nbsp;in) diameter celestial globe published in 1598 in Amsterdam by [[Biography:Petrus Plancius|Petrus Plancius]] and Jodocus Hondius and was depicted in Johann Bayer's star atlas ''[[Astronomy:Uranometria|Uranometria]]'' of 1603, and was likely conceived by Plancius from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman. French explorer and astronomer Nicolas-Louis de Lacaille gave its stars [[Astronomy:Bayer designation|Bayer designation]]s in 1756. The constellations Pavo, [[Astronomy:Grus (constellation)|Grus]], [[Astronomy:Phoenix (constellation)|Phoenix]] and [[Astronomy:Tucana|Tucana]] are collectively known as the "Southern Birds".

The constellation's brightest member, [[Astronomy:Alpha Pavonis|Alpha Pavonis]], is also known as Peacock and appears as a 1.91-[[Astronomy:Apparent magnitude|magnitude]] blue-white star, but is actually a [[Astronomy:Spectroscopic binary|spectroscopic binary]]. [[Astronomy:Delta Pavonis|Delta Pavonis]] is a nearby [[Astronomy:Sun|Sun]]-like star some 19.9 [[Astronomy:Light-year|light-year]]s distant. Six of the [[Astronomy:Star system|star system]]s in Pavo have been found to host planets, including [[Astronomy:HD 181433|HD 181433]] with a [[Astronomy:Super-Earth|super-Earth]], and [[Astronomy:HD 172555|HD 172555]] with evidence of a major interplanetary collision in the past few thousand years. The constellation contains [[Astronomy:NGC 6752|NGC 6752]], the fourth-brightest [[Astronomy:Globular cluster|globular cluster]] in the sky, and the [[Spiral galaxy|spiral galaxy]] [[Astronomy:NGC 6744|NGC 6744]], which closely resembles the [[Astronomy:Milky Way|Milky Way]] but is twice as large. Pavo displays an annual [[Astronomy:Meteor shower|meteor shower]] known as the Delta Pavonids, whose [[Astronomy:Radiant (meteor shower)|radiant]] is near the star [[Astronomy:Delta Pavonis|δ Pav]].<ref name="deltapavs">{{cite web |url=http://meteorshowersonline.com/showers/delta_pavonids.html |title=Delta Pavonids |work=Meteor Showers On-line |access-date=23 August 2013 |archive-url=https://web.archive.org/web/20130928035123/http://meteorshowersonline.com/showers/delta_pavonids.html |archive-date=2013-09-28 |url-status=dead }}</ref>

==History and mythology==

===History of the modern constellation===
[[File:Johann Bayer - Uraniometria - Southern Birds.jpg|thumb|right|Pavo (upper right), with the other southern birds, in its first appearance in a celestial atlas, Johann Bayer's ''Uranometria'']]
Pavo was one of the twelve constellations established by [[Biography:Petrus Plancius|Petrus Plancius]] from the observations of the southern sky by explorers Pieter Dirkszoon Keyser and Frederick de Houtman, who had sailed on the first Dutch trading expedition, known as the ''Eerste Schipvaart'', to the [[Place:East Indies|East Indies]]. It first appeared on a 35 cm (14&nbsp;in) 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 German cartographer Johann Bayer's ''[[Astronomy:Uranometria|Uranometria]]'' of 1603.<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 |publisher=self-published |access-date=23 August 2013}}</ref><!-- cites previous three sentences --> De Houtman included it in his southern star catalogue the same year under the Dutch name ''De Pauww'' {{gloss|The Peacock}}.<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=23 August 2013}}</ref> Pavo and the nearby constellations [[Astronomy:Phoenix (constellation)|Phoenix]], [[Astronomy:Grus (constellation)|Grus]], and [[Astronomy:Tucana|Tucana]] 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>

===The peacock in Greek mythology===
According to Mark Chartrand, former executive director of the [[Organization:National Space Institute|National Space Institute]], Plancius may not have been the first to designate this group of stars as a peacock: "In Greek myth the stars that are now the Peacock were Argos [or Argus], builder of the ship Argo. He was changed by the goddess Juno into a peacock and placed in the sky along with his ship."<ref>Mark R. Chartrand III (1983) Skyguide: A Field Guide for Amateur Astronomers, p. 172 ({{ISBN|0-307-13667-1}}).</ref><ref>See also Mike Dixon-Kennedy (1998) ''Greco-Roman Mythology'', pp. 45, 153 ({{ISBN|1-57607-129-4}}).</ref> Indeed, the peacock "symboliz[ed] the starry firmament" for the Greeks,<ref>J.C. Cooper (Thames & Hudson 1987) ''An Illustrated Encyclopaedia of Traditional Symbols'' Paperback, p. 127 ({{ISBN|978-0500271254}})</ref> and the goddess Hera was believed to drive through the heavens in a chariot drawn by peacocks.<ref>Ian Ridpath (James Clark & Co. 1988) ''Star Tales'', p. 99 ({{ISBN|978-0718826956}}).</ref>

The peacock and the "Argus" nomenclature are also prominent in a different myth, in which [[Biology:Io (mythology)|Io]], a beautiful princess of Argos, was lusted after by [[Religion:Zeus|Zeus]] (Jupiter). Zeus changed Io into a heifer to deceive his wife (and sister) Hera and couple with her. Hera saw through Zeus's scheme and asked for the heifer as a gift.  Zeus, unable to refuse such a reasonable request, reluctantly gave the heifer to Hera, who promptly banished Io and arranged for Argus Panoptes, a creature with one hundred eyes, to guard the now-pregnant Io from Zeus. Meanwhile, Zeus entreated [[Religion:Hermes|Hermes]] to save Io; Hermes used music to lull Argus Panoptes to sleep, then slew him. Hera adorned the tail of a peacock—her favorite bird—with Argus's eyes in his honor.<ref>{{cite book |last=Berens |first=E.M. |title=The Myths and Legends of Ancient Greece and Rome: A Handbook of Mythology |publisher=Europaeischer Hochschulverlag GmbH & Co |location=Bremen |page=26 |isbn=978-3-86741-511-8 |url=https://books.google.com/books?id=5MGG8_rFhrkC&pg=PA26 |orig-year=1894 |date=2010}}</ref><ref>[http://www.greekmythology.com/Myths/The_Myths/Zeus_s_Lovers/Io_/io_.html "Io"], Greek Mythology.com (accessed 11/19/2013).</ref>

As recounted in Ovid's ''Metamorphoses'', the death of Argus Panoptes also contains an explicit celestial reference: "Argus lay dead; so many eyes, so bright quenched, and all hundred shrouded in one night. Saturnia [Hera] retrieved those eyes to set in place among the feathers of her bird [the peacock, Pavo] and filled his tail with starry jewels."<ref>Ovid, Metamorphoses 1.720.</ref>
[[File:Johan Doppelmayr's celestial chart of Pavo and Indus.jpg|thumb|right|The constellations Pavo and Indus, featured (reversed) in the chart of the Southern Celestial Hemisphere by Johann Gabriel Doppelmayr in his Atlas Cœlestis, {{Circa|1742}}]]

It is uncertain whether the Dutch astronomers had the Greek mythos in mind when creating Pavo but, in keeping with other constellations introduced by Plancius through Keyser and De Houtmann, the "peacock" in the new constellation likely referred to the green peacock, which the explorers would have encountered in the East Indies, rather than the blue peacock known to the ancient Greeks.<ref name="ridpathpav">{{cite web |url=http://www.ianridpath.com/startales/pavo.html |work=Star Tales |title=Pavo – the Peacock |last1=Ridpath |first1=Ian |publisher=self-published |access-date=23 August 2013}}</ref>

===Equivalents in other cultures===
The Wardaman people of the Northern Territory in Australia saw the stars of Pavo and the neighbouring constellation [[Astronomy:Ara (constellation)|Ara]] as flying foxes.<ref name="darksparklers">{{cite book |last=Harney |first=Bill Yidumduma |author2=Cairns, Hugh C. |title=Dark Sparklers |publisher=Hugh C. Cairns |location=Merimbula, New South Wales |date=2004 |orig-year=2003 |edition=Revised |page=201 |isbn=978-0-9750908-0-0}}</ref>

==Characteristics==
Pavo is bordered by [[Astronomy:Telescopium|Telescopium]] to the north, [[Astronomy:Apus|Apus]] and Ara to the west, [[Astronomy:Octans|Octans]] to the south, and [[Astronomy:Indus (constellation)|Indus]] to the east and northeast. Covering 378 square degrees, it ranks 44th of the 88 modern constellations in size and covers 0.916% of the night sky.<ref name=bagnall>{{cite book |last=Bagnall |first=Philip M. |title=The Star Atlas Companion: What You Need to Know about the Constellations |publisher=Springer |location=New York |date=2012 |isbn=978-1-4614-0830-7 |page=338 |url=https://books.google.com/books?id=KcIg02TKW6QC&pg=PA338}}</ref> The three-letter abbreviation for the constellation, as adopted by the [[Organization:International Astronomical Union|International Astronomical Union]] in 1922, is "Pav".<ref name="pa30_469">{{cite journal |last=Russell |first=Henry Norris |title=The New International Symbols for the Constellations |journal=Popular Astronomy |volume=30 |pages=469–471 |bibcode=1922PA.....30..469R |date=1922}}</ref> The official constellation boundaries, as set by Belgian astronomer [[Biography:Eugène Joseph Delporte|Eugène Delporte]] in 1930, are defined by a polygon of 10 segments. In the [[Astronomy:Equatorial coordinate system|equatorial coordinate system]], the [[Right ascension|right ascension]] coordinates of these borders lie between {{RA|18|10.4}} and {{RA|21|32.4}}, while the [[Declination|declination]] coordinates are between −56.59° and −74.98°.<ref name="boundary">{{Cite journal |title=Pavo, constellation boundary |journal=The Constellations |publisher=International Astronomical Union |url=http://www.iau.org/public/constellations/#pav |access-date=23 August 2013}}</ref> As one of the deep southern constellations, it remains below the horizon at latitudes north of the 30th parallel in the [[Earth:Northern Hemisphere|Northern Hemisphere]], and is circumpolar at latitudes south of the 50th parallel in the [[Earth:Southern Hemisphere|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|date=1991 |pages=385, 388–389 |isbn=978-1-85410-088-7}}</ref>

==Features==

===Stars===
{{Further|Astronomy:List of stars in Pavo}}
[[File:Constellation Pavo.jpg|thumb|upright|left|The constellation Pavo as it can be seen by the naked eye]]
Although he depicted Pavo on his chart, Bayer did not assign its stars [[Astronomy:Bayer designation|Bayer designation]]s. French explorer and astronomer Nicolas-Louis de Lacaille labelled them Alpha to Omega in 1756, but omitted Psi and Xi, and labelled two pairs of stars close together Mu and Phi Pavonis. In 1879, American astronomer Benjamin Gould designated a star Xi Pavonis as he felt its brightness warranted a name, but dropped Chi Pavonis due to its faintness.<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 |isbn=978-0-939923-78-6 |pages=231–232}}</ref><!-- cites previous three sentences -->

Lying near the constellation's northern border with Telescopium is [[Astronomy:Alpha Pavonis|Alpha Pavonis]], the brightest star in Pavo.<ref name="motz" /> Its proper name—Peacock—is an English translation of the constellation's name.<ref name=bagnall/> It was assigned by the British HM Nautical Almanac Office in the late 1930s; the {{wipe|Royal Air Force}} insisted that all bright stars must have names, the star hitherto having lacked a proper name.<ref name="sadler1993">{{citation |last1=Sadler |first1=D.H. |title=A Personal History of H.M. Nautical Almanac Office |page=48 |publisher=Edited and privately published by Wilkins, G.A. |date=1993 |url=http://astro.ukho.gov.uk/nao/history/dhs_gaw/nao_perhist_0802_dhs.pdf |access-date=2013-08-27 |archive-date=2012-04-03 |archive-url=https://web.archive.org/web/20120403214348/http://astro.ukho.gov.uk/nao/history/dhs_gaw/nao_perhist_0802_dhs.pdf |url-status=dead }}</ref> Alpha has an [[Astronomy:Apparent magnitude|apparent]] (or visual) magnitude of 1.91 and [[Astronomy:Stellar classification|spectral type]] B2IV.<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Alpha+Pavonis |title=Peacock – Spectroscopic Binary |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=23 August 2013}}</ref> It is a [[Astronomy:Spectroscopic binary|spectroscopic binary]] system, one estimate placing the distance between the pair of stars as 0.21 [[Astronomy:Astronomical unit|astronomical unit]]s (AU), or half the distance between [[Astronomy:Mercury (planet)|Mercury]] and the Sun.<ref name="kaleralpha">{{cite web |url=http://stars.astro.illinois.edu/sow/peacock.html |title=Peacock |last=Kaler |first=James B. |work=Stars |publisher=University of Illinois |access-date=23 August 2013}}</ref> The two stars rotate around each other in a mere 11 days and 18 hours.<ref name="motz" /> The [[Astronomy:Star system|star system]] is located around 180 light years away from Earth.<ref name="kaleralpha" />

With an apparent magnitude of 3.43, [[Astronomy:Beta Pavonis|Beta Pavonis]] is the second-brightest star in the constellation. A white [[Astronomy:Giant star|giant]] of spectral class A7III,<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=beta+pav&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title=Beta Pavonis |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=23 August 2013}}</ref> it is an aging star that has used up the hydrogen fuel at its core and has expanded and cooled after moving off the [[Astronomy:Main sequence|main sequence]]. It lies 135 light years away from the [[Astronomy:Solar System|Solar System]].<ref name="kalerbeta">{{cite web |url=http://stars.astro.illinois.edu/sow/betapav.html |title=Beta Pavonis |last=Kaler |first=James B. |work=Stars |publisher=University of Illinois |access-date=23 August 2013 |date=24 September 2010}}</ref>

Lying a few degrees west of Beta is [[Astronomy:Delta Pavonis|Delta Pavonis]], a nearby Sun-like but more [[Astronomy:Stellar evolution|evolved]] star;<ref name="motz" /> this is a yellow subgiant of spectral type G8IV and apparent magnitude 3.56 that is only 19.9 light years distant from Earth.<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=delta+pav&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title=Delta Pavonis – Variable Star |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=23 August 2013}}</ref> East of Beta and at the constellation's eastern border with Indus is [[Astronomy:Gamma Pavonis|Gamma Pavonis]], a fainter, solar-type star 30 light years from Earth with a magnitude of 4.22 and stellar class F9V.<ref>{{cite journal |last1=Mosser, B. |display-authors=4 |last2=Deheuvels |first2=S. |last3=Michel |first3=E. |last4=Thévenin |first4=F. |last5=Dupret |first5=M.A. |last6=Samadi |first6=R. |last7=Barban |first7=C. |last8=Goupil |first8=M.J. |title=HD 203608, a Quiet Asteroseismic Target in the Old Galactic Disk |journal=Astronomy and Astrophysics |year=2008 |volume=488 |issue=2 |pages=635–642 |doi=10.1051/0004-6361:200810011 |bibcode=2008A&A...488..635M |arxiv=0804.3119|s2cid=15871263 }}</ref> Other nearby stars in Pavo are much fainter: [[Astronomy:SCR 1845-6357|SCR 1845-6357]] (the nearest star in Pavo) is a binary system with an apparent magnitude of 17.4 consisting of a [[Astronomy:Red dwarf|red dwarf]] and [[Astronomy:Brown dwarf|brown dwarf]] companion lying around 12.6 light years distant, while [[Astronomy:Gliese 693|Gliese 693]] is a red dwarf of magnitude 10.78 lying 19 light years away.<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?submit=display&bibdisplay=refsum&bibyear1=1850&bibyear2=%24currentYear&Ident=%403464606&Name=GJ+++693#lab_bib |title=GJ 693 – Variable Star |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=24 August 2013}}</ref>

Pavo contains several variable stars of note. [[Astronomy:Lambda Pavonis|Lambda Pavonis]] is a bright [[Astronomy:Irregular variable|irregular variable]] ranging between magnitudes 3.4 and 4.4; this variation can be observed with the unaided eye. Classed as a Gamma Cassiopeiae variable or [[Astronomy:Shell star|shell star]],<ref name="inglis">{{cite book |last=Inglis |first=Mike |title=Astronomy of the Milky Way: Observer's Guide to the Southern Sky |publisher=Springer |location=New York |date=2004 |pages=153–154 |isbn=978-1-85233-742-1 |url=https://books.google.com/books?id=1r0qvMjSCGAC&q=Circinus+inglis&pg=SA3-PA31}}</ref> it is of spectral type B2II-IIIe and lies around 1430 light years distant from Earth.<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=lambda+pavonis&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title=Lambda Pavonis – Be Star |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=24 August 2013}}</ref> [[Astronomy:Kappa Pavonis|Kappa Pavonis]] is a [[Astronomy:W Virginis variable|W Virginis variable]]—a subclass of [[Astronomy:Type II Cepheid|Type II Cepheid]].<ref name="inglis" /> It ranges from magnitude 3.91 to 4.78 over 9 days and is a yellow-white [[Astronomy:Supergiant|supergiant]] pulsating between spectral classes F5I-II and G5I-II.<ref>{{cite web |url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=25119 |title=Kappa Pavonis |publisher=AAVSO |work=International Variable Star Index |date=7 January 2011 |access-date=24 August 2013}}</ref> [[Astronomy:NU Pavonis|NU]] and V Pavonis are pulsating [[Astronomy:Semiregular variable star|semiregular variable]] [[Astronomy:Red giant|red giant]] stars. NU has a spectral type M6III and ranges from magnitude 4.9 to 5.3,<ref>{{cite web |url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=25016 |title=NU Pavonis |publisher=AAVSO |work=International Variable Star Index |date=7 January 2011 |access-date=24 August 2013}}</ref> while V Pavonis ranges from magnitude 6.3 to 8.2 over two periods of 225.4 and 3735 days concurrently.<ref name="inglis" /> V is a [[Astronomy:Carbon star|carbon star]]<ref name="gray_corbally" group="note">C6 is equivalent to a class M2–M3 star, the 4 shows the strength of the Swan bands on a scale of 1 (weak) to 5 (strong), and the Nb indicates bands of the chemical element [[Chemistry:Niobium|niobium]]. See:<br />{{cite book |author=Gray, Richard O. |author2=Corbally, Christopher J. |title=Stellar Spectral Classification |date=2009 |publisher=Princeton University Press |location=Princeton, New Jersey |page=309 |isbn=978-0-691-12511-4}}</ref> of spectral type C6,4(Nb)<ref>{{cite web |url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=24725 |title=V Pavonis |publisher=AAVSO |work=International Variable Star Index |date=7 January 2011 |access-date=24 August 2013}}</ref> with a prominent red hue.<ref name="inglis" />

Located in the west of the constellation and depicting the peacock's tail are [[Astronomy:Eta Pavonis|Eta]] and [[Astronomy:Xi Pavonis|Xi Pavonis]].<ref name="streicher">{{cite web |last=Streicher |first=Magda |date=October 2010 |title=Pavo{{snd}}A Fanciful Bird |publisher=The Astronomical Society of Southern Africa |work=Deepsky Delights |url=http://assa.saao.ac.za/sections/deepsky/delights/2010_oct_deepsky_delights.pdf |archive-url=https://web.archive.org/web/20130927073955/http://assa.saao.ac.za/sections/deepsky/delights/2010_oct_deepsky_delights.pdf |archive-date=2013-09-27 |access-date=26 August 2013}}</ref> At apparent magnitude 3.6, Eta is a luminous orange giant of spectral type K2II some 350 light years distant from Earth.<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Eta+Pavonis&submit=SIMBAD+search |title=Eta Pavonis |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=26 August 2013}}</ref> Xi Pavonis is a multiple star system visible in small telescopes as a brighter orange star and fainter white companion.<ref name="inglis" /> Located around 470 light years from Earth, the system has a magnitude of 4.38.<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Xi+Pavonis&submit=SIMBAD+search |title=Xi Pavonis |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=25 August 2013}}</ref> AR Pavonis is a faint but well-studied eclipsing binary composed of a red giant and smaller hotter star some 18000 light years from Earth. It has some features of a cataclysmic variable, the smaller component most likely having an accretion disc.<ref>{{cite journal |author=Skopal, A. |display-authors=4 |author2=Djurašević, G. |author3=Jones, A. |author4=Drechsel, H. |author5=Rovithis-Livaniou, H. |author6=Rovithis, P. |date=2000 |title=A Photometric Study of the Eclipsing Symbiotic Binary AR Pavonis |journal=[[Organization:Monthly Notices of the Royal Astronomical Society|Monthly Notices of the Royal Astronomical Society]] |volume=311 |issue=2 |pages=225–233 |doi=10.1046/j.1365-8711.2000.03040.x |bibcode=2000MNRAS.311..225S|doi-access=free }}</ref> The visual magnitude ranges from 7.4 to 13.6 over 605 days.<ref>{{cite web |url=http://www.aavso.org/vsx/index.php?view=detail.top&oid=24791 |title=AR Pavonis |publisher=AAVSO |work=International Variable Star Index |date=4 January 2010 |access-date=25 August 2013}}</ref>

In November 2018, the 8th magnitude star, [[Astronomy:HD 186302|HD 186302]] became the second star identified to be a solar sibling, this one being particularly sun like, same spectra G2, virtually the same mass as well, with a twin spectra revealing identical metallicity.<ref>[http://astrobob.areavoices.com/2018/11/24/did-astronomers-just-find-the-suns-sister Did Astronomers Just Find The Sun’s Sister?] Bob P. King, November 24, 2018</ref>

===Planetary systems and debris disks===
Six stars with planetary systems have been found. Three planets have been discovered in the system of the orange star [[Astronomy:HD 181433|HD 181433]], an inner super-Earth with an orbital period of 9.4 days and two outer gas giants with periods of 2.6 and 6 years respectively.<ref name="bouchy2009">{{cite journal |doi=10.1051/0004-6361:200810669 |title=The HARPS Search for Southern Extra-solar Planets. XVII. Super-Earth and Neptune-mass Planets in Multiple Planet Systems HD 47186 and HD 181433 |url=http://www.aanda.org/articles/aa/full_html/2009/11/aa10669-08/aa10669-08.html |last1=Bouchy |first1=François |last2=Mayor | first2=Michel |last3=Lovis |first3=Christophe |last4=Udry |first4=Stéphane |last5=Benz |first5=Willy |last6=Bertaux |first6=Jean-Loup |last7=Delfosse |first7=Xavier |last8=Mordasini |first8=Christoph |last9=Pepe |first9=Francesco |last10=Queloz |first10=Didier |last11=Ségransan |first11=Damien |journal=Astronomy and Astrophysics |volume=496 |issue=2 |pages=527–531 |year=2009 |arxiv=0812.1608 |bibcode=2009A&A...496..527B |s2cid=117778593 }}</ref> [[Astronomy:HD 196050|HD 196050]] and [[Astronomy:HD 175167|HD 175167]] are yellow G-class Sun-like stars, while [[Astronomy:HD 190984|HD 190984]] is an F-class main sequence star slightly larger and hotter than the Sun; all three are accompanied by a gas giant companion.<ref>{{cite journal |url=http://www3.interscience.wiley.com/journal/118945825/abstract |archive-url=https://archive.today/20121204153037/http://www3.interscience.wiley.com/journal/118945825/abstract |url-status=dead |archive-date=2012-12-04 |author=Jones |title=Extrasolar Planets around HD 196050, HD 216437 and HD 160691 |journal=[[Organization:Monthly Notices of the Royal Astronomical Society|Monthly Notices of the Royal Astronomical Society]] |date=2002 |volume=337 |issue=4 |pages=1170–1178 |doi=10.1046/j.1365-8711.2002.05787.x |format=abstract |display-authors=4 |last2=Butler |first2=R. Paul |last3=Marcy |first3=Geoffrey W. |last4=Tinney |first4=Chris G. |last5=Penny |first5=Alan J. |last6=McCarthy |first6=Chris |last7=Carter |first7=Brad D. |arxiv=astro-ph/0206216 |bibcode=2002MNRAS.337.1170J|s2cid=119520409 }}</ref><ref>{{cite journal |last1=Arriagada |first1=Pamela |display-authors=4 |last2=Butler |first2=R. Paul |last3=Minniti |first3=Dante |last4=López-Morales |first4=Mercedes |last5=Shectman |first5=Stephen A. |last6=Adams |first6=Fred C. |last7=Boss |first7=Alan P. |last8=Chambers |first8=John E. |title=Five Long-period Extrasolar Planets in Eccentric Orbits from the Magellan Planet Search Program |journal=[[Astronomy:The Astrophysical Journal|The Astrophysical Journal]] |date=2010 |arxiv=1001.4093 |doi=10.1088/0004-637X/711/2/1229 |volume=711 |issue=2 |pages=1229–1235 |bibcode=2010ApJ...711.1229A|s2cid=118682009 }}</ref><ref name="santos2010">{{cite journal |doi=10.1051/0004-6361/200913489 |title=The HARPS Search for Southern Extra-solar Planets XXI. Three New Giant Planets Orbiting the Metal-poor Stars HD 5388, HD 181720, and HD 190984 |url=http://www.aanda.org/articles/aa/full_html/2010/04/aa13489-09/aa13489-09.html |last1=Santos |first1=Nuno C. |display-authors=4 |last2=Mayor |first2=Michel |last3=Benz |first3=Willy |last4=Bouchy |first4=François |last5=Figueira |first5=Pedro |last6=Lo Curto |first6=Gaspare |last7=Lovis |first7=Christophe |last8=Melo |first8=Claudio |last9=Moutou |first9=Claire |last10=Naef |first10=Dominique |last11=Pepe |first11=Francesco |last12=Queloz |first12=Didier |last13=<!-- de -->Sousa |first13=Sérgio <!-- António -->Gonçalves |last14=Udry |first14=Stéphane |journal=Astronomy and Astrophysics |volume=512 |issue=A47 |page=A47 |date=2010 |arxiv=0912.3216 |bibcode=2010A&A...512A..47S |s2cid=118675798 }}</ref> [[Astronomy:HD 172555|HD 172555]] is a young white A-type main sequence star, two planets of which appear to have had a major collision in the past few thousand years. Spectrographic evidence of large amounts of [[Chemistry:Silicon dioxide|silicon dioxide]] gas indicates the smaller of the two, which had been at least the size of Earth's moon, was destroyed,  and the larger, which was at least the size of Mercury, was severely damaged. Evidence of the collision was detected by NASA's [[Astronomy:Spitzer Space Telescope|Spitzer Space Telescope]].<ref>{{Cite journal |title=Abundant Circumstellar Silica Dust And Sio Gas Created By A Giant Hypervelocity Collision In The ~12 Myr HD172555 System |first=C. M. |last=Lisse |display-authors=4 |author2=Chen, C.H. |author3=Wyatt, M.C. |author4=Morlok, A. |author5=Song, I. |author6=Bryden, G. |author7=Sheehan, P. |journal=[[Astronomy:The Astrophysical Journal|The Astrophysical Journal]] |date=16 June 2009 |pages=984–997 |doi=10.1088/0004-637X/701/2/2019 |volume=701 |bibcode=2009ApJ...701.2019L |issue=2 |arxiv=0906.2536|s2cid=56108044 }}</ref> In the south of the constellation, [[Astronomy:Epsilon Pavonis|Epsilon Pavonis]] is a 3.95-magnitude white main sequence star of spectral type A0Va located around 105 light years distant from Earth.<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-basic?Ident=Epsilon+Pavonis&submit=SIMBAD+search |title=Epsilon Pavonis |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=29 August 2013}}</ref> It appears to be surrounded by a narrow ring of dust at a distance of 107&nbsp;AU.<ref>{{cite journal |author=Booth, Mark |display-authors=4 |author2=Kennedy, Grant |author3=Sibthorpe, Bruce |author4=Matthews, Brenda C. |author5=Wyatt, Mark C. |author6=Duchêne, Gaspard |author7=Kavelaars, J.J. |author8=Rodriguez, David |author9=Greaves, Jane S.|author10=Koning, Alice |author11=Vican, Laura |author12=Rieke, George H. |author13=Su, Kate Y.L. |author14=Moro-Martín, Amaya |author15=Kalas, Paul |year=2013 |title=Resolved Debris Discs Around A Stars in the Herschel DEBRIS Survey |journal=Monthly Notices of the Royal Astronomical Society |volume=428 |issue=2 |pages=1263–1280 |bibcode=2013MNRAS.428.1263B |arxiv=1210.0547 |doi=10.1093/mnras/sts117|s2cid=53072716 }}</ref>

===Deep-sky objects===
[[File:Star cluster NGC 6752.jpg|thumb|The globular cluster NGC 6752 contains an estimated 100,000 stars.]]
The [[Astronomy:Deep-sky object|deep-sky object]]s in Pavo include [[Astronomy:NGC 6752|NGC 6752]], the fourth-brightest [[Astronomy:Globular cluster|globular cluster]] in the sky, after <!-- in decreasing order of brightness (or increasing order of apparent magnitude) -->[[Astronomy:Omega Centauri|Omega Centauri]], 47&nbsp;Tucanae and Messier&nbsp;22.{{r|APODNASA<!-- stating that ngc 6752 is in the direction of pavo -->}}<ref name="nasa.messier22">{{Cite web | title = Messier 22 | author = | work = NASA | date = | access-date = 21 July 2023 | url = https://archive.today/20230718052546/https://www.nasa.gov/feature/goddard/2017/messier-22/ | quote = }}<!-- stating that messier 22 has an apparent magnitude of 5.1 --></ref><ref name="nasa.ngc6752">{{Cite web | title = Caldwell 93 | author = | work = NASA | date = | access-date = 21 July 2023 | url = https://archive.today/20230718054846/https://www.nasa.gov/feature/goddard/caldwell-93/ | quote = }}<!-- stating that ngc 6752 has an apparent magnitude of 5.4 --></ref> An estimated 100 light years across, it is thought to contain 100,000 stars.<ref name="APODNASA">{{Cite APOD|title=Globular Star Cluster NGC 6752 |date=5 July 2013|access-date=23 August 2013}}</ref><!-- cites previous two sentences --> Barely visible behind the cluster is a [[Astronomy:Dwarf spheroidal galaxy|dwarf spheroidal galaxy]] known as [[Astronomy:Bedin I|Bedin I]].<ref>{{Cite web|author=ESA/Hubble Information Centre|title=Hubble fortuitously discovers a new galaxy in the cosmic neighbourhood|url=https://phys.org/news/2019-01-hubble-fortuitously-galaxy-cosmic-neighbourhood.html|website=Phys.org|access-date=1 February 2019|archive-url=https://web.archive.org/web/20190201050615/https://phys.org/news/2019-01-hubble-fortuitously-galaxy-cosmic-neighbourhood.html|archive-date=1 February 2019|date=31 January 2019|quote=Bedin 1, which lies far behind the foreground globular cluster NGC 6752.|url-status=live}}</ref> Lying three degrees to the south is [[Astronomy:NGC 6744|NGC 6744]],<ref name="motz" /> a [[Spiral galaxy|spiral galaxy]]  around 30 million light years away from Earth that resembles the [[Astronomy:Milky Way|Milky Way]], but is twice its diameter.<ref>{{cite web |url=http://www.eso.org/public/news/eso1118/ |title=A Postcard from Extragalactic Space? A spiral galaxy that resembles our Milky Way |last=Hook |first=Richard |date=1 June 2011 |work=European Southern Observatory |publisher=ESO Images and Downloads |access-date=23 August 2013}}</ref> A [[Astronomy:Type Ib and Ic supernovae|type 1c supernova]] was discovered in the galaxy in 2005;<ref name="mobberley">{{cite book |title=The Caldwell Objects And How to Observe Them |first=Martin |last=Mobberley |pages=208–209 |url=https://books.google.com/books?id=amPrWoOWgHcC&q=supernova+pavo&pg=PA208 |publisher=Springer |location=New York |date=1999 |isbn=978-1-4419-0326-6}}</ref> known as SN2005at, it peaked at magnitude 16.8.<ref>{{cite web |url=http://www.rochesterastronomy.org/sn2005/ |title=Bright Supernovae – 2005 |last=Bishop |first=David |date=10 September 2013 |work=Astronomy Section |publisher=Rochester Academy of Science |access-date=22 September 2013 |location=Rush, New York}}</ref> The dwarf galaxy [[Astronomy:IC 4662|IC 4662]] lies 10 arcminutes northeast of Eta Pavonis,<ref name="inglis" /> and is of magnitude 11.62.<ref>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=IC+4662 |title=IC 4662 – Blue compact Galaxy |work=SIMBAD Astronomical Database |publisher=Centre de Données astronomiques de Strasbourg |access-date=24 August 2013}}</ref> Located only 8 million light years away, it has several regions of [[Astronomy:Starburst region|high star formation]].<ref>{{cite web |url=http://www.spacetelescope.org/images/opo0919d/ |title=Hubble ACS image of IC 4662 |last=McQuinn |first=K. |date=30 April 2009 |work=Hubble website |publisher=European Space Agency (ESA) |access-date=24 August 2013}}</ref> The 14th-magnitude galaxy IC 4965 lies 1.7 degrees west of Alpha Pavonis, and is a central member of the [[Astronomy:Shapley Supercluster|Shapley Supercluster]].<ref name="streicher" /> The [[Astronomy:Galactic superwind|galactic wind]] bearing [[Astronomy:NGC 6810|NGC 6810]] and the interacting [[Astronomy:NGC 6872|NGC 6872]]/[[Astronomy:IC 4970|IC 4970]] galaxies lie 87 and 212 million light-years away from Earth respectively.

===Meteor showers===
Pavo is the [[Astronomy:Radiant (meteor shower)|radiant]] of two annual meteor showers: the Delta Pavonids and August Pavonids. Appearing from 21 March to 8 April and generally peaking around 5 and 6 April, Delta Pavonids are thought to be associated with Comet Grigg-Mellish.{{sfn|Levy|2008|p = 109}} The shower was discovered by Michael Buhagiar from Perth, Australia,<ref>{{cite book |first=Petrus Matheus Marie |last=Jenniskens |title=Meteor Showers and Their Parent Comets |publisher=Cambridge University Press |location=Cambridge, UK |page=315 |date=2006 |isbn=978-0-521-85349-1 |url=https://books.google.com/books?id=QpajMuyXG8AC&pg=PA315}}</ref> who observed meteors on six occasions between 1969 and 1980.<ref>{{cite web |url=http://meteorshowersonline.com/showers/delta_pavonids.html |title=Delta Pavonids |last=Kronk |first=Gary W. |work=Meteor Showers Online |publisher=self-published |access-date=26 August 2013 |archive-url=https://web.archive.org/web/20130928035123/http://meteorshowersonline.com/showers/delta_pavonids.html |archive-date=2013-09-28 |url-status=dead }}</ref> The August Pavonids peak around 31 August and are thought to be associated with the [[Astronomy:Halley's Comet|Halley]]-type Comet Levy (P/1991 L3).{{sfn|Levy|2008|p = 117}}

{{Clear}}

==See also==
* [[Astronomy:Pavo in Chinese astronomy|Pavo in Chinese astronomy]]

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

==References==
{{Reflist}}

==Sources==
* {{cite book |last=Levy |first=David H. |title=David Levy's Guide to Observing Meteor Showers |publisher=Cambridge University Press |location=Cambridge, UK|date=2008 |isbn=978-0-521-69691-3}}

==External links==
* [http://astrojan.nhely.hu/pavo.htm The clickable Pavo]
* {{Commons and category-inline}}

{{Stars of Pavo}}
{{Constellations}}

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{{DEFAULTSORT:Pavo (Constellation)}}
[[Category:Pavo (constellation)| ]]
[[Category:Constellations listed by Petrus Plancius]]
[[Category:Southern constellations]]
[[Category:Constellations]]

{{Sourceattribution|Pavo (constellation)}}