View source for Astronomy:Indus (constellation)

{{Short description|Constellation in the southern celestial hemisphere}}
{{Infobox constellation|
name = Indus |
abbreviation = Ind |
genitive = Indi |
pronounce = {{IPAc-en|ˈ|ɪ|n|d|ʊ|s}},<br>genitive {{IPAc-en|ˈ|ɪ|n|d|aɪ}} |
symbolism = the Indian<ref>{{Cite book|url=https://books.google.com/books?id=5m_A_AsQVPUC&q=indus+indian+constellation&pg=PA70|title = Constellations: The Stars and Stories|isbn = 9781402708008|last1 = Sasaki|first1 = Chris|year = 2003}}</ref> |
RA = {{RA|20|28|40.6308}}–{{RA|23|27|59.4799}}{{sfn|IAU, ''The Constellations'', Indus}} |
dec = {{dec|-44.9588585}}–{{dec|-74.4544678}}{{sfn|IAU, ''The Constellations'', Indus}} |
family = Bayer |
quadrant = SQ4 |
areatotal = 294 |
arearank = 49th |
numbermainstars = 3 |
numberbfstars = 16 |
numberstarsplanets = 3 |
numberbrightstars = 0 |
numbernearbystars = 1 |
brighteststarname = The Persian ([[Astronomy:Alpha Indi|α Ind]]) |
starmagnitude = 3.11 |
neareststarname = [[Astronomy:Epsilon Indi|Epsilon Indi]] |
stardistancely = 11.83 |
stardistancepc = 3.62 |
numbermessierobjects = none |
meteorshowers = none<ref>{{cite web
 | author=Anonymous | date=February 3, 2007
 | url=http://www.amsmeteors.org/showers.html
 | title=Meteor Showers | publisher=American Meteor Society
 | access-date=2008-05-07 }}</ref> |
bordering = [[Astronomy:Microscopium|Microscopium]]<br />[[Astronomy:Sagittarius (constellation)|Sagittarius]] (corner)<br />[[Astronomy:Telescopium|Telescopium]]<br />[[Astronomy:Pavo (constellation)|Pavo]]<br />[[Astronomy:Octans|Octans]]<br />Tucana<br />[[Astronomy:Grus (constellation)|Grus]] |
latmax = 15 |
latmin = [[Earth:South Pole|90]] |
month = September |
notes=
}}
'''Indus''' is a [[Astronomy:Constellation|constellation]] in the southern sky first professionally surveyed by Europeans in the 1590s and mapped on a globe by [[Biography:Petrus Plancius|Petrus Plancius]] by early 1598. It was included on a plate illustrating southern constellations in Bayer's sky atlas ''[[Astronomy:Uranometria|Uranometria]]'' in 1603.  It lies well south of the Tropic of Capricorn but its triangular shape can be seen for most of the year from the [[Astronomy:Equator|Equator]]. It is elongated from north to south and has a complex boundary.  The English translation of its name is generally given as ''the Indian'', though it is unclear which indigenous people the constellation was originally supposed to represent.

==Features==
[[Image:Constellation Indus.jpg|thumb|350px|The constellation Indus as it can be seen by the naked eye.]]
Indus lacks stars of the top 100 in brightness viewed from the solar system (apparent magnitude).  Two of its stars rank of third magnitude and three of fourth magnitude.
=== Bright stars ===
[[Astronomy:Alpha Indi|Alpha Indi]], its brightest, is an orange giant of magnitude 3.1, 101 light-years away. [[Astronomy:Beta Indi|Beta Indi]] is an orange giant of magnitude 3.7, 600 light-years distant. [[Astronomy:Delta Indi|Delta Indi]] is a white star of magnitude 4.4, 185 light-years from Earth.  The three form a near-perfect right-angled triangle, such that Beta marks the right angle and is in the south-east.

[[Astronomy:Epsilon Indi|Epsilon Indi]] is one of the closest stars to [[Astronomy:Earth|Earth]], approximately 11.8 [[Light year|light year]]s away. It is an orange dwarf of magnitude 4.7, meaning that the yellow dwarf [[Astronomy:Sun|Sun]] is slightly hotter and larger.{{sfn|Ridpath|Tirion|2001|pp=162-163}} The system has been discovered to contain a pair of binary brown dwarfs, and has long been a prime candidate in SETI studies.<ref>{{cite book | first=Robert | last=Burnham |author2=Luft, Herbert A. | date=1978 | title=Burnham's Celestial Handbook: An Observer's Guide to the Universe Beyond the Solar System | url=https://archive.org/details/burnhamscelestia02robe | url-access=registration | publisher=Courier Dover Publications | isbn=0-486-23568-8 }}</ref><ref>{{cite journal | last=Lawton | first=A. T. | title=CETI from Copernicus |journal=Spaceflight | date=1975 | volume=17 | pages=328–330 | bibcode=1975SpFl...17..328L }}</ref> This star has the third-highest [[Astronomy:Proper motion|proper motion]] of all visible to the unaided eye, as ranks behind [[Astronomy:Groombridge 1830|Groombridge 1830]] and [[Astronomy:61 Cygni|61 Cygni]], and the ninth-highest overall. This will move the star into [[Astronomy:Tucana|Tucana]] around 2640.  It figures directly between Alpha and Beta.

Indus is home to one bright [[Astronomy:Binary star|binary star]]. [[Astronomy:Theta Indi|Theta Indi]] is a binary star divisible in small amateur telescopes, 97 light-years from Earth. Its primary is a white star of magnitude 4.5 and its secondary is a white star of magnitude 7.0.{{sfn|Ridpath|Tirion|2001|pp=162-163}} It figures close to the hypotenuse of the right-angled triangle of Alpha, Beta and Delta, the three brightest stars of Indus.
=== Variable stars ===
T Indi is the only bright [[Astronomy:Variable star|variable star]] in Indus. It is a semi-regular, deeply coloured [[Astronomy:Red giant|red giant]] with a period of 11 months, 1900 light-years away. Its minimum magnitude is 7 and its maximum: 5.{{sfn|Ridpath|Tirion|2001|pp=162-163}}

=== Galaxies ===
Galaxies include [[Astronomy:NGC 7038|NGC 7038]],  [[Astronomy:NGC 7049|NGC 7049]], and [[Astronomy:NGC 7090|NGC 7090]].
[[File:NGC7038 - HST - Potw2245a.jpg|thumb|left|The spiral galaxy NGC 7038 ([[Astronomy:Hubble Space Telescope|Hubble Space Telescope]] image)]]
=== Supernovae ===
All Sky Automated Survey for SuperNovae (ASAS-SN) in 2015 detected a [[Astronomy:Superluminous supernova|superluminous supernova]], named [[Astronomy:ASASSN-15lh|ASASSN-15lh]] (also designated SN 2015L<ref>[[Organization:Central Bureau for Astronomical Telegrams|Central Bureau for Astronomical Telegrams]] [http://www.cbat.eps.harvard.edu/iau/cbet/004100/CBET004120.txt CBET 4120]</ref>). Based on the study conducted by Subo Dong and team from the Kavli Institute for Astronomy and Astrophysics (KIAA) at Peking University, it was approximately doubly luminous to any supernova detected, and at peak was almost 50 times more intrinsically luminous than the [[Astronomy:Milky Way|Milky Way]].
Its distance: approximately 3.82 gigalight-years, denoting an age approximately half that of the universe.<ref name=phys>{{cite web|author1=Carnegie Institution for Science|title=Most-luminous supernova ever discovered|url=http://phys.org/news/2016-01-most-luminous-supernova.html|publisher=phys.org|access-date=January 15, 2016|date=January 14, 2016}}</ref>

==History==

[[File:Johann Bayer - Uraniometria - Southern Birds.jpg|thumb|250px|Indus (top middle) in an extract from Johann Bayer's ''Uranometria'', its first appearance in a celestial atlas.]]
The constellation was created by [[Biography:Petrus Plancius|Petrus Plancius]] who made a fairly large celestial globe from the observations of Pieter Dirkszoon Keyser and Frederick de Houtman.{{sfn|Ridpath|Tirion|2001|pp=162-163}} The first depiction of this constellation in a celestial atlas followed in Johann Bayer's ''[[Astronomy:Uranometria|Uranometria]]'' of 1603.<ref>{{cite book | first=Michael E. | last=Bakich | date=1995 | title=The Cambridge Guide to the Constellations | publisher={{wipe|Cambridge University Press}} | isbn=0-521-44921-9 | url=https://archive.org/details/cambridgeguideto00baki }}</ref><ref>{{cite journal | last=Sawyer Hogg | first=Helen | title=Out of Old Books (Pieter Dircksz Keijser, Delineator of the Southern Constellations) | journal=Journal of the Royal Astronomical Society of Canada | date=1951 | volume=45 | page=215 | bibcode=1951JRASC..45..215S}}</ref> Plancius portrayed the figure as a nude male with three arrows in one hand and one in the other, as a native, lacking quiver and bow.<ref>{{cite book | first=Richard Hinckley | last=Allen | date=1963 | title=Star Names, Their Lore and Meaning | publisher=[[Social:Dover Publications|Dover Publications]] | location=New York | isbn=0-486-21079-0 | url=https://archive.org/details/starnamestheirlo00alle }}</ref> It is among the twelve constellations introduced by Keyser and de Houtman, which first appeared on a celestial globe in 1598.

==See also==
* [[Astronomy:IAU designated constellations|IAU-recognized constellations]]
* Indus (Chinese astronomy)
{{-}}

==References==
{{reflist}}

==Sources==
* {{cite web |ref={{sfnRef|IAU, ''The Constellations'', Indus}} |title=Indus |work=The Constellations |publisher=International Astronomical Union |url=https://www.iau.org/public/themes/constellations/#ind}}
* {{citation |title = Stars and Planets Guide |last1 = Ridpath |first1 = Ian |last2 = Tirion |first2 = Wil |year = 2001 |publisher = Princeton University Press |isbn = 0-691-08913-2}}
* Ian Ridpath and Wil Tirion (2007). ''Stars and Planets Guide'', Collins, London. {{ISBN|978-0-00-725120-9}}. Princeton University Press, Princeton. {{ISBN|978-0-691-13556-4}}.

==External links==
* [http://www.allthesky.com/constellations/indus/constell.html The Deep Photographic Guide to the Constellations: Indus]
* [http://astrojan.nhely.hu/indus.htm The clickable Indus]
* [http://www.starrynightphotos.com/constellations/indus.htm Starry Night Photography: Indus Constellation]
* [http://www.ianridpath.com/startales/indus.html Star Tales–Indus]

{{Stars of Indus}}
{{navconstel}}
{{Sky|21|00|00|-|55|00|00|10}}

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

{{Sourceattribution|Indus (constellation)}}