{{Short description|Planetary nebula in the constellation of Lupus}} {{ Planetary nebula | | image = [[Image:Retinanebel.jpg|250px]] |caption= [[Hubble Space Telescope]] view of IC 4406 | name = [[Index Catalogue|IC]] 4406 | type = Planetary | epoch = [[J2000]] | ra = {{RA|14|22|26.278}}<ref name="simbad">{{cite web | title=SIMBAD Astronomical Database | work=Results for IC 4406 | url=http://simbad.u-strasbg.fr/Simbad | access-date=2006-12-19}}</ref> | dec = {{DEC|-44|09|04.35}}<ref name="simbad" /> | dist_ly = [[1 E19 m|2.0]] [[light-year|kly]] (600 [[parsec|pc]])<ref name="ODelletal2003" /> | radius_ly = | appmag_v = | size_v = | constellation = [[Lupus (constellation)|Lupus]] | diameter_ly = | absmag_v = -0.3 | notes = - | names = Retina Nebula<ref name="ODelletal2002" /> }}
'''IC 4406''', sometimes known as the '''Retina Nebula''',<ref name=Chadwick/> is a [[planetary nebula]] near the western border of the [[constellation]] [[Lupus (constellation)|Lupus]], the Wolf. It has dust clouds and has the shape of a [[torus]]. Despite this, it looks somewhat rectangular because it is seen from its side as viewed from [[Earth]], almost in the plane<ref name="ODelletal2003"/> of its equator.
==Structure== IC 4406 is [[bipolar nebula|bipolar]] and appears to be a [[prolate spheroid]] with strong concentrations of material in its [[equator]].<ref name="ODelletal2002"/> This kind of structure is a natural product of a bipolar model.<ref name="ODelletal2002" /> The knots of IC 4406 have a "lacy" appearance and have no ordered symmetry towards the [[white dwarf|central star]].<ref name="ODelletal2003" /> The knots have no tails.<ref name="ODelletal2003"/> None of the features have bright edges.<ref name="ODelletal2003" /> At least 5 faint ring-like structures, seen as arcs north and south of the main nebula, have been detected in [[Very Large Telescope]] observations.<ref name="Ramos-Larios"/>
The central star of the planetary nebula has a [[spectral type]] similar to that of a [[Wolf–Rayet star|Wolf–Rayet]] star.<ref name=Gonz/> An analysis of ''[[Gaia (spacecraft)|Gaia]]'' data suggests that it may be a [[binary star|binary system]].<ref name=Chornay/>
==Gallery== <gallery> The planetary nebula IC 4406 seen with MUSE and the AOF.jpg|IC 4406 seen with [[Multi Unit Spectroscopic Explorer|MUSE instrument]] and the Adaptive Optics Facility.<ref name=eso/> </gallery>
==See also== * [[Planetary nebula]]
==References== {{Reflist|refs=
<ref name=Chadwick>{{cite book |last1=Chadwick |first1=Stephen |last2=Cooper |first2=Ian |title=Imaging the Southern Sky |date=11 December 2012 |publisher=Springer |isbn=978-1461447498 |page=149}}</ref>
<ref name="ODelletal2003">{{cite conference | author=O'dell, C. R. | display-authors=4 | author2=Balick, B. | author3=Hajian, A. R. | author4=Henney, W. J. | author5=Burkert, A. | title=Knots in Planetary Nebulae | conference=Winds, Bubbles, and Explosions: a conference to honor John Dyson, Pátzcuaro, Michoacán, México, September 9–13, 2002 | editor=S. J. Arthur & W. J. Henney | book-title=[[Revista Mexicana de Astronomía y Astrofísica]] (Serie de Conferencias) | url=http://www.astroscu.unam.mx/~rmaa/ | date=2003 | volume=15 | pages=29–33 | bibcode=2003RMxAC..15...29O | access-date=2006-12-19 | archive-date=2018-05-01 | archive-url=https://web.archive.org/web/20180501131545/http://www.astroscu.unam.mx/~rmaa/ | url-status=dead }}</ref>
<ref name="Ramos-Larios">{{cite journal |last1=Ramos-Larios |first1=G. |last2=Toalá |first2=J. A. |last3=Rodríguez-González |first3=J. B. |last4=Guerrero |first4=M. A. |last5=Gómez-González |first5=V. M. A. |title=Rings and arcs around evolved stars - III. Physical conditions of the ring-like structures in the planetary nebula IC 4406 revealed by MUSE |journal=Monthly Notices of the Royal Astronomical Society |date=June 2022 |volume=513 |issue=2 |pages=2862–2868 |doi=10.1093/mnras/stac605 |doi-access=free |arxiv=2203.01254 |bibcode=2022MNRAS.513.2862R |hdl=10261/275661 |hdl-access=free }}</ref>
<ref name="ODelletal2002">{{cite journal |author1=O'Dell, C. R. |author2=Balick, B. |author3=Hajian, A. R. |author4=Henney, W. J. |author5=Burkert, A. | title=Knots in Nearby Planetary Nebulae | journal=The Astronomical Journal | date=2002 | volume=123 | issue=6 | pages=3329–3347 | bibcode=2002AJ....123.3329O | doi=10.1086/340726 | doi-access=free }}</ref>
<ref name=Gonz>{{cite journal|doi=10.1051/0004-6361/202141916|title=Planetary nebulae in Gaia EDR3: Central star identification, properties, and binarity|year=2021|last1=González-Santamaría|first1=I.|last2=Manteiga|first2=M.|last3=Manchado|first3=A.|last4=Ulla|first4=A.|last5=Dafonte|first5=C.|last6=López Varela|first6=P.|journal=Astronomy & Astrophysics|volume=656|pages=A51|arxiv=2109.12114|bibcode=2021A&A...656A..51G|s2cid=237940344}}</ref>
<ref name=Chornay>{{cite journal|doi=10.1051/0004-6361/202140288|title=Towards a more complete sample of binary central stars of planetary nebulae with Gaia|year=2021|last1=Chornay|first1=N.|last2=Walton|first2=N. A.|last3=Jones|first3=D.|last4=Boffin|first4=H. M. J.|last5=Rejkuba|first5=M.|last6=Wesson|first6=R.|journal=Astronomy & Astrophysics|volume=648|pages=A95|arxiv=2101.01800|bibcode=2021A&A...648A..95C|s2cid=230770301}}</ref>
<ref name=eso>{{cite web|title=Cutting-edge Adaptive Optics Facility Sees First Light - Spectacular improvement in the sharpness of MUSE images|url=https://www.eso.org/public/news/eso1724/|website=www.eso.org|access-date=4 August 2017}}</ref>
}}
== External links == * {{commonscat-inline}}
{{Lupus (constellation)}}
[[Category:Planetary nebulae]] [[Category:Lupus (constellation)]] [[Category:IC objects|4406]]
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