Editing Grus (constellation) (section)

===Deep-sky objects===
[[File:From Cosmic Spare Tyre to Ethereal Blossom.tif|right|thumb|[[IC 5148]], the spare-tyre nebula as imaged by the [[European Southern Observatory|ESO]] Faint Object Spectrograph and Camera (EFOSC2) on the [[New Technology Telescope]] at La Silla]]
Nicknamed the spare-tyre nebula,<ref name="ESO12">{{cite web|url=http://www.eso.org/public/images/potw1242a/|title=From Cosmic Spare Tyre to Ethereal Blossom|last=ESO|date=2012|work=Picture of the Week|publisher=European Southern Observatory|access-date=6 February 2014}}</ref> [[IC 5148]] is a [[planetary nebula]] located around 1 degree west of Lambda Gruis.<ref name="streicher">{{cite web | last = Streicher  | first = Magda  | date = December 2010 | title = Grus—An Elegant Starry Bird  | publisher = The Astronomical Society of Southern Africa  | work = Deepsky Delights  | url =http://www.mnassa.org.za/html/Dec2010/2010MNASSA..69..Dec..229.pdf |pages = 56–59  | access-date = 7 February 2014}}</ref> Around 3000 light-years distant, it is expanding at 50 kilometres a second, one of the fastest rates of expansion of all planetary nebulae.<ref name="ESO12"/>

Northeast of Theta Gruis are four interacting galaxies known as the Grus Quartet.<ref name=Bakich>{{cite book|last=Bakich|first=Michael E.|title=1,001 Celestial Wonders to See Before You Die|url=https://archive.org/details/celestialwonders00baki_814|url-access=limited|date=2010|publisher=Springer Science+Business Media, LLC|location=New York, New York|isbn=978-1-4419-1777-5|page=[https://archive.org/details/celestialwonders00baki_814/page/n342 334]}}</ref> These galaxies are [[NGC 7552]], [[NGC 7590]], [[NGC 7599]], and [[NGC 7582]].<ref name=koribalski>{{cite web|url=http://www.atnf.csiro.au/people/bkoribal/ngc7582/grus_hi.html|title=The Grus-Quartet|author=Koribalski, Bärbel |date=1996|access-date=28 January 2014}}</ref> The latter three galaxies occupy an area of sky only 10 arcminutes across and are sometimes referred to as the "Grus Triplet," although all four are part of a larger loose group of galaxies called the IC 1459 Grus Group.<ref name="O'Meara"/> NGC 7552 and 7582 are exhibiting high [[Starburst galaxy|starburst]] activity; this is thought to have arisen because of the tidal forces from interacting.<ref name=koribalski/> Located on the border of Grus with Piscis Austrinus,<ref name="streicher"/> [[IC 1459]] is a peculiar E3 giant [[elliptical galaxy]]. It has a fast counterrotating stellar core, and shells and ripples in its outer region.<ref>{{cite journal |author1= Verdoes Kleijn, Gijs A. |author2=van der Marel, Roeland P. |author3-link=C. Marcella Carollo |author3=Carollo, C. Marcella |author4=de Zeeuw, P. Tim  |date=2000|title=The Black Hole in IC 1459 from Hubble Space Telescope Observations of the Ionized Gas Disk|journal=The Astronomical Journal|volume=120|issue=3 |pages=1221–37 |arxiv = astro-ph/0003433 |bibcode = 2000AJ....120.1221V |doi = 10.1086/301524 }}</ref><!-- cites previous two sentences --> The galaxy has an apparent magnitude of 11.9<ref>{{cite web |url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=IC+1459+&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title =IC 1459 – LINER-type Active Galaxy Nucleus |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 7 February 2014}}</ref> and is around 80 million light-years distant.<ref name="streicher"/>

[[NGC 7424]] is a [[barred spiral galaxy]] with an apparent magnitude of 10.4.<ref>{{cite web |url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC+7424 |title = NGC 7424 – Galaxy in Group of Galaxies |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 4 February 2014}}</ref> located around 4 degrees west of the Grus Triplet.<ref name="streicher"/> Approximately 37.5 million light-years distant, it is about 100,000 light-years in diameter, has well defined spiral arms and is thought to resemble the [[Milky Way]].<ref>{{Cite APOD|title=Grand Spiral Galaxy NGC 7424 |date=8 January 2013|access-date=4 February 2014}}</ref> Two [[ultraluminous X-ray source]]s and one [[supernova]] have been observed in NGC 7424.<ref name="soria06">{{cite journal |author1=Soria, R. |author2=Kuncic, Z. |author3=Broderick, J. W. |author4=Ryder, S. D. | title = Multiband Study of NGC 7424 and its Two Newly-discovered ULXs | journal = Monthly Notices of the Royal Astronomical Society |date=2006 | volume = 370 | issue = 4 | pages = 1666–76 | bibcode = 2006MNRAS.370.1666S | doi = 10.1111/j.1365-2966.2006.10629.x|doi-access=free |arxiv = astro-ph/0606080 |s2cid=17098189 }}</ref> [[SN 2001ig]] was discovered in 2001 and classified as a [[Type IIb supernova#Type IIb supernovae|Type IIb supernova]], one that initially showed a weak hydrogen line in its [[stellar spectrum|spectrum]], but this emission later became undetectable and was replaced by lines of oxygen, magnesium and calcium, as well as other features that resembled the spectrum of a [[Type Ib supernova]].<ref>{{cite journal|author1=Maund, Justyn R. |author2=Wheeler, J. Craig |author3=Patat, Ferdinando |author4=Wang, Lifan |author5=Baade, Dietrich |author6=Höflich, Peter A. |date=2007|title=Spectropolarimetry of the Type IIb Supernova 2001ig*|journal=The Astrophysical Journal|volume=671|issue=2|pages=1944–1958|arxiv = 0709.1487 |bibcode = 2007ApJ...671.1944M |doi = 10.1086/523261 |s2cid=15234633 }}</ref> A massive star of [[spectral type]] F, A or B is thought to be the surviving binary companion to SN 2001ig, which was believed to have been a [[Wolf–Rayet star]].<ref name="ryder06">{{cite journal |author1=Ryder, Stuart D. |author2=Murrowood, Clair E. |author3=Stathakis, Raylee A. | title = A Post-mortem Investigation of the Type IIb Supernova 2001ig| journal = Monthly Notices of the Royal Astronomical Society | date = 2006 | volume = 369
| issue = 1 | pages = L32–L36 | bibcode = 2006MNRAS.369L..32R| doi = 10.1111/j.1745-3933.2006.00168.x|doi-access=free |arxiv = astro-ph/0603336 |s2cid=15543433 }}</ref>

Located near Alnair is [[NGC 7213]],<ref name="streicher"/> a face-on type 1 [[Seyfert galaxy]] located approximately 71.7 million light-years from Earth.<ref name="hameed">{{cite journal|author1=Hameed, Salman |author2=Blank, David L. |author3=Young, Lisa M. |author4=Devereux, Nick |date=2001|title= The Discovery of a Giant Hα Filament in NGC 7213|journal=The Astrophysical Journal|volume=546|issue=2|pages=L97–L100|url=https://cds.cern.ch/record/476765/files/0011208.pdf |archive-url=https://web.archive.org/web/20210224231211/https://cds.cern.ch/record/476765/files/0011208.pdf |archive-date=2021-02-24 |url-status=live|arxiv = astro-ph/0011208 |bibcode = 2001ApJ...546L..97H |doi = 10.1086/318865 |s2cid=2657286 }}</ref> It has an apparent magnitude of 12.1.<ref>{{cite web |url =http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC%207213 |title = NGC 7213 – Type 1 Seyfert Galaxy |work = SIMBAD Astronomical Database|publisher=Centre de Données astronomiques de Strasbourg |access-date = 5 February 2014}}</ref> Appearing undisturbed in visible light, it shows signs of having undergone a collision or merger when viewed at longer wavelengths, with disturbed patterns of ionized hydrogen including a filament of gas around 64,000 light-years long.<ref name="hameed"/> It is part of a group of ten galaxies.<ref name=fouque>{{cite journal|last1=Fouque|first1=P.|last2=Proust|first2=D.|last3=Quintana|first3=H.|last4=Ramirez|first4=A.|year=1993|title=Dynamics of the Pavo-Indus and Grus Clouds of Galaxies|journal=Astronomy and Astrophysics Supplement Series|volume=100|issue=3|pages=493–500|bibcode=1993A&AS..100..493F}}</ref>

[[NGC 7410]] is a spiral galaxy discovered by British astronomer [[John Herschel]] during observations at the [[Cape of Good Hope]] in October 1834. The galaxy has a visual magnitude of 11.7 and is approximately 122 million light-years distant from Earth.<ref name="O'Meara">{{cite book|last=O'Meara|first=Stephen James|title=Deep Sky Companions: Southern Gems|date=2013|publisher=Cambridge University Press|location=New York, New York|isbn=978-1-107-01501-2|pages=418–26|url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC%207213}}</ref>