Editing Musca (section)

===Deep-sky objects===
Located on the border with Circinus is the unusual [[planetary nebula]] [[NGC 5189]],<ref name="streicher"/> estimated to be around 1750&nbsp;light-years away from Earth.<ref name=sbngc5189>{{cite web |url=http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NGC+5189&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id |title=NGC 5189 – Planetary Nebula |work=[[SIMBAD|SIMBAD Astronomical Database]] |publisher=Centre de Données astronomiques de Strasbourg |access-date=29 December 2013}}</ref> Its complex structure is due to multiple ejections of material from the ageing central star, which are distorted by the presence of a likely binary companion.<ref>{{cite web|url=http://www.nasa.gov/mission_pages/hubble/science/ngc5189.html|title=A Cosmic Holiday Ornament, Hubble-Style|last=Villard|first=Ray |date=18 December 2012|work=Hubble Space Telescope|publisher=NASA|access-date=31 December 2013}}</ref> Located 2.4° east of Eta Muscae is the magnitude-12.9 [[Engraved Hourglass Nebula]] (MyCn&nbsp;18),<ref>{{cite book |title=1001 Celestial Wonders to See Before You Die: The Best Sky Objects for Star Gazers |first=Michael E. |last=Bakich |publisher=Springer |location=New York, New York |date=2010 |isbn=978-1-4419-1777-5 |page=159 |url=https://books.google.com/books?id=qEhpS7d5ZdAC&pg=PA159}}</ref> which lies about 8000 light-years distant from Earth.<ref name="sahai99">{{cite journal|author=Sahai, Raghvendra |display-authors=4  |author2=Dayal, Aditya |author3=Watson, Alan M. |author4=Trauger, John T. |author5=Stapelfeldt, Karl R. |author6=Burrows, Christopher J. |author7=Gallagher, John S. III |author8=Scowen, Paul A. |author9=Hester, J. Jeff |author10=Evans, Robin W. |author11=Ballester, Gilda E. |author12=Clarke, John T. |author13=Crisp, David |author14=Griffiths, Richard E. |author15=Hoessel, John G. |author16=Holtzman, Jon A. |author17=Krist, John |author18=Mould, Jeremy R.|date=1999|title=The Etched Hourglass Nebula MYCN 18. I. ''Hubble Space Telescope'' Observations |bibcode-access=free |journal=The Astronomical Journal|volume=118|issue=1 |pages=468–76|doi=10.1086/300939|bibcode = 1999AJ....118..468S |doi-access=free }}</ref> To Eta's west lies [[IC 4191]], a compact bluish planetary nebula of magnitude 10.6,<ref name="Griffiths">{{cite book|last=Griffiths|first=Martin|date=2012|title=Planetary Nebulae and How to Observe Them |pages=198–200| isbn=978-1-4614-1782-8 |publisher=Springer |location=New York, New York |url=https://books.google.com/books?id=gsI1S_KVDxoC&q=musca+nebula&pg=PA198}}</ref> thought to lie around 10,750 light-years away from Earth.<ref name=zhang93>{{cite journal|last=Zhang|first=C.Y.|date=1993|title=On the Distance to Galactic Planetary Nebulae|journal=Astrophysical Journal, Part 1|volume=410|issue=1|pages=239–50|bibcode=1993ApJ...410..239Z|doi=10.1086/172740}}</ref> West of Epsilon Muscae is [[NGC 4071]], a large, diffuse planetary nebula of magnitude 12.7 with a magnitude 12 central star,<ref name="Griffiths"/> thought to lie around 4000 light-years away from Earth.<ref name=zhang93/> The [[Coalsack Nebula]] is a [[dark nebula]] located mainly in neighbouring Crux that intrudes into Musca.<ref>{{cite book|last=Darling|first=David J. |title=The Universal Book of Astronomy: from the Andromeda Galaxy to the Zone of Avoidance|publisher=Wiley|location=Hoboken, New Jersey|date=2004|page=351|isbn=0-471-26569-1}}</ref> [[NGC 4463]] is an [[open cluster]] located on its southwestern border.<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, New York|date=2004|page=83|isbn=1-85233-742-7|url=https://books.google.com/books?id=1r0qvMjSCGAC&pg=SA3-PA12}}</ref> Around five light-years across, it is located around 3400 light-years away.<ref name=bagnall/>

The comparatively old [[globular cluster]] [[NGC 4833]] near Delta Muscae was catalogued by Lacaille in 1755.<ref name="streicher"/> It is 21,200&nbsp;light-years distant and somewhat obscured by dust clouds near the [[galactic plane]]. The globular cluster [[NGC 4372]] near Gamma Muscae is fainter and likewise partially obscured by dust, but spans more [[arc minute]]s.<ref name="turnleft">{{cite book|last=Consolmagno|first=Guy |title=Turn Left at Orion: Hundreds of Night Sky Objects to See in a Home Telescope – and How to Find Them|publisher=Cambridge University Press|location=Cambridge, United Kingdom|date=2011|page=235 |isbn=978-1-139-50373-0|url=https://books.google.com/books?id=h3712RgWkOYC&pg=PA235}}</ref><!-- cites previous two sentences --> It is 18,900&nbsp;light-years away from Earth and 23,000&nbsp;light-years distant from the centre of the Milky Way. Its extremely low [[metallicity]] indicates it is very old—one of the oldest clusters in the Milky Way.<ref name="o'meara">{{cite book |title=Deep-Sky Companions: Southern Gems |first=Stephen James |last=O'Meara |publisher=Cambridge University Press|location=Cambridge, United Kingdom |date=2013 |pages=218–21 |isbn=978-1-107-01501-2|url=https://books.google.com/books?id=S5QIEKns33sC&pg=PA220}}</ref><!-- cites previous two sentences --> Extending south from it is the [[Dark Doodad Nebula]], resembling a dark L-shaped river through a bright field of stars.<ref name="Coe2007">{{cite book |url=https://books.google.com/books?id=roXyxpcc9MsC&pg=PA95 |title=Nebulae and How to Observe Them |publisher=Springer |location=New York, New York |first=Steven R. |last=Coe |page=95 |date=2007 |isbn=978-1-84628-482-3}}</ref> Another [[dark nebula]] in the constellation is [[BHR 71]].