Editing Eta Carinae (section)

===Discovery and naming===
There is no reliable evidence of η&nbsp;Carinae being observed or recorded before the 17th&nbsp;century, although Dutch navigator [[Pieter Dirkszoon Keyser|Pieter Keyser]] described a fourth-magnitude star at approximately the correct position around 1595–1596, which was copied onto the celestial globes of [[Petrus Plancius]] and [[Jodocus Hondius]] and the 1603 ''[[Uranometria]]'' of [[Johann Bayer]]. [[Frederick de Houtman]]'s independent star catalogue from 1603 does not include η&nbsp;Carinae among the other 4th&nbsp;magnitude stars in the region. The earliest firm record was made by [[Edmond Halley]] in 1677 when he recorded the star simply as ''Sequens'' (i.e. "following" relative to another star) within a new constellation [[Robur Carolinum]]. His ''Catalogus Stellarum Australium'' was published in 1679.<ref name="Halley 1679">{{cite book |last=Halley |first=Edmund |author-link=Edmond Halley |year=1679 |title=Catalogus stellarum australium; sive, Supplementum catalogi Tychenici, exhibens longitudines et latitudines stellarum fixarum, quae, prope polum Antarcticum sitae, in horizonte Uraniburgico Tychoni inconspicuae fuere, accurato calculo ex distantiis supputatas, & ad annum 1677 completum correctas ... Accedit appendicula de rebus quibusdam astronomicis |url=http://babel.hathitrust.org/cgi/pt?id=mdp.39015007000170;view=1up;seq=24 |url-status=dead |publisher=T. James |location=London, UK |page=13 |archive-url=https://archive.today/20151106091831/http://babel.hathitrust.org/cgi/pt?id=mdp.39015007000170;view=1up;seq=24 |archive-date=6 November 2015}}</ref> The star was also known by the [[Bayer designation]]s η&nbsp;Roboris Caroli, [[Eta|η]]&nbsp;Argus, or η Navis.<ref name=frew>{{cite journal |last=Frew |first=David J. |year=2004 |title=The historical record of η&nbsp;Carinae. I.&nbsp;The visual light curve, 1595–2000 |journal=The Journal of Astronomical Data |volume=10 |issue=6 |pages=1–76 |bibcode=2004JAD....10....6F }}</ref> In 1751 [[Nicolas-Louis de Lacaille]] gave the stars of [[Argo Navis]] and [[Robur Carolinum]] a single set of Greek letter Bayer designations within his constellation Argo, and designated three areas within Argo for the purposes of using Latin letter designations three times over. The letter [[Eta|η]] fell within the keel portion of the ship which was later to become the constellation [[Carina (constellation)|Carina]].<ref name=warner>{{cite journal |last=Warner |first=Brian |year=2002 |title=Lacaille 250&nbsp;years on |journal=Astronomy and Geophysics |volume=43 |issue=2 |pages=2.25–2.26 |issn=1366-8781 |bibcode=2002A&G....43b..25W |doi=10.1046/j.1468-4004.2002.43225.x |doi-access=free}}</ref> It was not generally known as η&nbsp;Carinae until 1879, when the stars of Argo Navis were finally given the epithets of the daughter constellations in the ''Uranometria Argentina'' of [[Benjamin Apthorp Gould|Gould]].<ref name=wagman>{{cite book |last=Wagman |first=Morton |title=Lost Stars: Lost, missing and troublesome stars from the catalogues of Johannes Bayer, Nicholas Louis de&nbsp;Lacaille, John Flamsteed, and sundry others |publisher=The McDonald & Woodward Publishing Company |location=Blacksburg, VA |year=2003 |pages=7–8, 82–85 |isbn=978-0-939923-78-6 }}</ref>

η&nbsp;Carinae is too far south to be part of the [[Twenty-Eight Mansions|mansion-based]] [[Chinese astronomy|traditional Chinese astronomy]], but it was mapped when the [[Chinese constellations#The Southern Asterisms (近南極星區)|Southern Asterisms]] were created at the start of the 17th&nbsp;century. Together with [[HD 90853|s Carinae]], [[λ Centauri]] and [[λ Muscae]], η&nbsp;Carinae forms the [[Asterism (astronomy)|asterism]] {{lang|zh|海山}} ([[Carina (Chinese astronomy)|Sea and Mountain]]).<ref name="Chen Jiu Jin 2005">{{cite book |script-title=zh:中國星座神 |title=Chinese horoscope mythology |author=陳久金 (Chen Jiu Jin) |publisher=台灣書房出版有限公司 (Taiwan Book House Publishing Co., Ltd.) |date=2005 |isbn=978-986-7332-25-7 |lang=zh}}</ref> η&nbsp;Carinae has the names Tseen She (from the Chinese 天社 [Mandarin: ''tiānshè''] "Heaven's altar") and Foramen. It is also known as {{lang|zh|海山二}} ({{lang|zh-Latn|Hǎi Shān èr}}, {{langx|en|the Second Star of Sea and Mountain}}).<ref name="Chen Huihua 2006">{{cite web |script-title=zh:天文教育資訊網 |title=Activities of Exhibition and Education in Astronomy |editor=陳輝樺 (Chen Huihua) |url=http://aeea.nmns.edu.tw/2006/0607/ap060728.html |website=nmns.edu.tw |date=28 July 2006 |access-date=30 December 2012 |language=zh |archive-date=13 May 2013 |archive-url=https://web.archive.org/web/20130513091029/http://aeea.nmns.edu.tw/2006/0607/ap060728.html |url-status=dead }}</ref>

Halley gave an approximate [[apparent magnitude]]&nbsp;4 at the time of discovery, which has been calculated as magnitude&nbsp;3.3 on the modern scale. The handful of possible earlier sightings suggest that η&nbsp;Carinae was not significantly brighter than this for much of the 17th&nbsp;century.<ref name=frew/> Further sporadic observations over the next 70&nbsp;years show that η&nbsp;Carinae was probably around 3rd&nbsp;magnitude or fainter, until Lacaille reliably recorded it at 2nd magnitude in 1751.<ref name=frew/> It is unclear whether η&nbsp;Carinae varied significantly in brightness over the next 50&nbsp;years; there are occasional observations such as [[William Burchell]]'s at 4th&nbsp;magnitude in 1815, but it is uncertain whether these are just re-recordings of earlier observations.<ref name=frew/>