View source for Chamaeleon

{{Short description|Constellation in the Southern Sky}}
{{about|the constellation|the animal|Chameleon|other uses|Chameleon (disambiguation)}}
{{Infobox constellation
| name = Chamaeleon
| abbreviation = Cha
| genitive = Chamaeleontis
| pronounce = {{IPAc-en|k|ə|ˈ|m|iː|l|i|ən}}, genitive {{IPAc-en|k|ə|ˌ|m|iː|l|i|ˈ|ɒ|n|t|ᵻ|s}}
| symbolism = the [[Chameleon]]
| RA = {{RA|07|26|36.5075}}–{{RA|13|56|26.6661}}<ref name=boundary>{{Cite journal | title=Chamaeleon, constellation boundary | journal=The Constellations | publisher=[[International Astronomical Union]]|url=https://www.iau.org/public/themes/constellations/#cha | access-date=15 February 2014 }}</ref>
| dec= {{dec|-75.2899170}}–{{dec|-83.1200714}}<ref name=boundary/>
| family = [[Bayer Family|Bayer]]
| areatotal = 132
| arearank = 79th
| numbermainstars = 3
| numberbfstars = 16
| numberbrightstars = 0
| numbernearbystars = 2
| brighteststarname = [[Alpha Chamaeleontis|α Cha]]
| starmagnitude = 4.05
| neareststarname = [[SCR 1138-7721]]
| stardistancely = 63.45
| stardistancepc = 19.45
| numbermessierobjects = 0
| meteorshowers = 0
| bordering = [[Musca]]<br />[[Carina (constellation)|Carina]]<br />[[Volans]]<br />[[Mensa (constellation)|Mensa]]<br />[[Octans]]<br />[[Apus]]
| latmax = [[5th parallel north|5]]
| latmin = [[South Pole|90]]
| month = April
| notes=
}}
'''Chamaeleon''' ({{IPAc-en|k|ə|ˈ|m|iː|l|i|ən}}) is a small [[constellation]] in the deep [[southern celestial hemisphere|southern sky]]. It is named after the [[chameleon]], a kind of [[lizard]]. It was first defined in the end of the 16th century.

== History ==

[[File:Chameleon Constellation.png|thumb|The constellation Camaeleon (Chamaeleon)  as depicted in [[Johann Gabriel Doppelmayr]]'s ''Atlas Coelestis'', ca. 1742.]]
Chamaeleon was one of twelve constellations created by [[Petrus Plancius]] from the observations of [[Pieter Dirkszoon Keyser]] and [[Frederick de Houtman]].{{sfn|Ridpath|Tirion|2017|p=118}} It first appeared on a 35-cm diameter celestial globe published in 1597 (or 1598) in [[Amsterdam]] by Plancius and [[Jodocus Hondius]].<!-- The preceding is not covered by Staal (1988) --> [[Johann Bayer]] was the first [[uranography|uranographer]] to put Chamaeleon in a celestial atlas. It was one of many constellations created by European explorers in the 15th and 16th centuries out of unfamiliar Southern Hemisphere stars.{{sfn|Staal|1988|p=260}}

== Features ==
[[Image:Constellation Chamaeleon.jpg|thumb|left|300px|The constellation Chamaeleon as it can be seen by the naked eye.]]

=== Stars ===
{{see also|List of stars in Chamaeleon}}

There are four bright stars in Chamaeleon that form a compact diamond-shape approximately 10 degrees from the [[south celestial pole]] and about 15 degrees south of [[Alpha Crucis|Acrux]], along the axis formed by Acrux and [[Gamma Crucis]]. [[Alpha Chamaeleontis]] is a white-hued star of magnitude 4.1, 63 light-years from Earth. [[Beta Chamaeleontis]] is a blue-white hued star of magnitude 4.2, 271 light-years from Earth. [[Gamma Chamaeleontis]] is a red-hued giant star of magnitude 4.1, 413 light-years from Earth. The other bright star in Chamaeleon is [[Delta Chamaeleontis]], a wide [[double star]]. The brighter star is [[Delta2 Chamaeleontis|Delta<sup>2</sup> Chamaeleontis]], a blue-hued star of magnitude 4.4. [[Delta1 Chamaeleontis|Delta<sup>1</sup> Chamaeleontis]], the dimmer component, is an orange-hued giant star of magnitude 5.5. They both lie about 350 light years away.{{sfn|Ridpath|Tirion|2017|p=118}}

Chamaeleon is also the location of [[Cha 110913]], a unique dwarf star or proto solar system.

=== Deep-sky objects ===
[[File:An Active Centre ESO 021-G004.jpg|thumb|left|Spiral galaxy ESO 021-G004.<ref>{{cite web |title=An Active Centre |url=https://www.spacetelescope.org/images/potw1951a/ |website=www.spacetelescope.org |access-date=23 December 2019 |language=en}}</ref>]]
In 1999, a nearby [[open cluster]] was discovered centered on the star [[Eta Chamaeleontis|η Chamaeleontis]]. The cluster, known as either
the [[Eta Chamaeleontis cluster]] or Mamajek 1, is 8 million years old, and lies 316 [[light years]] from Earth.{{sfn|Luhman|Steeghs|2004|p=917}}

The constellation contains a number of [[molecular clouds]] (the [[Chamaeleon complex|Chamaeleon dark clouds]]) that are forming low-mass [[T Tauri star]]s. The cloud complex lies some 400 to 600 [[light years]] from Earth, and contains tens of thousands of solar masses of gas and dust. The most prominent cluster of T Tauri stars and young B-type stars are in the Chamaeleon I cloud, and are associated with the reflection nebula [[IC 2631]].

Chamaeleon contains one planetary nebula, [[NGC 3195]], which is fairly faint. It appears in a telescope at about the same apparent size as [[Jupiter]].{{sfn|Ridpath|Tirion|2017|p=118}}

== Equivalents ==
In [[Chinese astronomy]], the stars that form Chamaeleon were classified as the [[Chinese constellations#The Southern Asterisms (近南極星區)|Little Dipper]] ({{zh|labels=no|c=小斗|p=Xiǎodǒu}}) among the [[Chinese constellations#The Southern Asterisms (近南極星區)|Southern Asterisms]] ({{zh|labels=no|t=近南極星區|p=Jìnnánjíxīngōu}}) by [[Xu Guangqi]].<ref>{{in lang|zh}} [http://aeea.nmns.edu.tw/2006/0607/ap060728.html AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 28 日].</ref> Chamaeleon is sometimes also called the Frying Pan in Australia.<ref>{{cite web |title=Chamaeleon Constellation |url=http://www.topastronomer.com/StarCharts/Constellations/Chamaeleon.php |website=Top Astronomer |access-date=7 June 2019 |archive-date=19 January 2012 |archive-url=https://web.archive.org/web/20120119115704/http://www.topastronomer.com/StarCharts/Constellations/Chamaeleon.php |url-status=dead }}</ref>

==See also==
* [[Chamaeleon (Chinese astronomy)]]
* [[IAU designated constellations|IAU-recognized constellations]]

== Citations ==
{{reflist}}

== References ==
* {{citation |first1 = Ian |last1 = Ridpath |first2 = Wil |last2 = Tirion |year = 2017 |title = Stars and Planets Guide |publisher = Princeton University Press |isbn = 978-0-691-17788-5}}
* {{citation |first = Julius D.W. |last = Staal |title = The New Patterns in the Sky: Myths and Legends of the Stars |publisher = The McDonald and Woodward Publishing Company |year = 1988 |isbn = 0-939923-04-1}}
* {{citation |first1 = K.L.|last1 = Luhman |first2 = D.|last2 = Steeghs |title = Spectroscopy of Candidate Members of the η Chamaeleontis and MBM 12 Young Associations|magazine=The Astrophysical Journal|volume=609|issue=2|pages=917–924|year=2004|publisher=IOPscience|doi=10.1086/421291|arxiv = astro-ph/0403684 |bibcode = 2004ApJ...609..917L |language=en|doi-access=free}}

== External links ==
{{Commons}}
* [https://www.allthesky.com/constellations/chamaeleon/ The Deep Photographic Guide to the Constellations: Chamaeleon]
* [http://astrojan.nhely.hu/chamael.htm The clickable Chamaeleon]
* [https://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1999ApJ...516L..77M&amp;db_key=AST&amp;data_type=HTML&amp;format=&amp;high=43a3b4e6f826104 "The eta Chamaeleontis Cluster: A Remarkable New Nearby Young Open Cluster" (Mamajek, Lawson, & Feigelson 1999)]
* [https://webda.physics.muni.cz/cgi-bin/ocl_page.cgi?cluster=mamajek+1 "WEBDA open cluster database entry for Mamajek 1"]
* [http://www.ianridpath.com/startales/chamaeleon.html Ian Ridpath's Star Tales – Chamaeleon]
* [https://theskylive.com/sky/deepsky/ngc3620-object NGC 3620 Barred spiral galaxy]

{{Stars of Chamaeleon}}
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[[Category:Chamaeleon| ]]
[[Category:Southern constellations]]
[[Category:Constellations listed by Petrus Plancius]]