View source for Sh 2-106

{{Short description|Emission nebula in the constellation Cygnus}}
{{Infobox nebula
| name = Sh 2-106
| image = Star-forming region S106 (captured by the Hubble Space Telescope).jpg
| caption =Sharpless 2-106
| type = H II region
| subtype= [[bipolar nebula]]
| epoch = J2000.0
| ra = {{RA|20|27|27.1}}<ref name="simbad">{{cite simbad
  | title=SH 2-106
  | accessdate=2013-01-13}}</ref>
| dec = {{DEC|+37|22|39}}<ref name="simbad" />
| dist_ly = 2,000
| dist_pc = 600
| appmag_v =
| size_v = 3′ × 3′
| constellation  = [[Cygnus (constellation)|Cygnus]]
| absmag_v =
| notes =
| names = S106
}}
'''Sh 2-106''',<ref name="nasa-sa">{{cite web |url=http://www.nasa.gov/mission_pages/hubble/science/snow-angel.html |title=Hubble Serves Up a Holiday Snow Angel |date=6 Dec 2011 |author=NASA, ESA, and the Hubble Heritage Team (STScI/AURA) |accessdate=13 Jan 2013 }}</ref> also known as the '''Celestial Snow Angel''', is an [[emission nebula]] and a [[star formation]] region in the constellation [[Cygnus (constellation)|Cygnus]].  It is a [[H II region]] estimated to be around 2,000 [[Light year|light years]] (600&nbsp;[[parsec|pc]]) from [[Earth]], in an isolated area of the [[Milky Way]].<ref name="nasa-sa" />

In the center of the nebula is a young and massive star that emits jets of hot gas from its poles, forming the bipolar structure.  Dust that surrounds the star is also ionized by it.  The nebula spans about 2 light-years across.<ref name="esa">{{cite web |url=http://www.esa.int/Our_Activities/Space_Science/Young_star_rebels_against_its_parent_cloud |title=Young star rebels against its parent cloud |date=15 Dec 2011 |accessdate=13 Jan 2013}}</ref>

==Central star==
The central star, a source of infrared radiation usually referred to as S106 IR or S106 IRS 4. <ref name="apod">{{Cite APOD |title=Star Forming Region S106  |date=7 Nov 2011 |access-date=13 Jan 2013}}</ref>  It is a massive star, approximately 15 solar masses.  Two jets of matter streaming from its poles heat surrounding matter to a temperature of around 10,000&nbsp;°C.<ref name="esa" />  Dust that is not ionized by the star's jets reflect light from the star.  With an estimated surface temperature of 37,000&nbsp;K, it is classified as a [[stellar classification|type O8]] star.  It loses around 10<sup>−6</sup> [[solar mass|<math>\begin{smallmatrix}M_\odot\end{smallmatrix}</math>]] per year in solar winds, ejecting material at around 100&nbsp;km/s.<ref>{{cite journal |title =Radio images of the bipolar H II region S106 |last1=Bally |first1=J. |last2=Snell |first2=R.L. |last3=Predmore |first3=R. |date=1 Sep 1983 |pages=154–162 |volume =272 |journal =Astrophysical Journal, Part 1 |bibcode=1983ApJ...272..154B |doi =10.1086/161272 |issn=0004-637X}}</ref>

Studies of images has revealed that the star-forming region has also created hundreds of low-mass [[brown dwarf]] stars<ref name="apod" /> and [[protostar]]s.<ref name="harvard-verylow">{{cite journal |title=Very Low Luminosity Young Cluster and the Luminosity and Mass Functions in S106 |first1=Yumiko |last1=Oasa |first2=Motohide |last2=Tamura |last3=Nakajima |first3=Yasushi |last4=Itoh |first4=Itoh |last5=Maihara |first5=Toshinori |last6=Iwamuro |first6=Fumihiko |last7=Motohara |first7=Kentaro |last8=Hayashi |first8=Saeko S.|author8-link=Saeko Hayashi |last9=Hayashi |first9=Masahiko |date=Mar 2006 |journal=The Astronomical Journal|pages=965–978 |doi=10.1086/500086 |bibcode=2006AJ....131.1608O |volume=131 |issue=3|display-authors=9 |last10=Kaifu |first10=Norio |doi-access=free }}</ref>

==References==
{{reflist}}

==External links==
*{{APOD |date=16 February 2016|title=Star Forming Region S106}}


{{Sh2 objects}}
{{Cygnus (constellation)}}

[[Category:H II regions]]
[[Category:Emission nebulae]]
[[Category:Cygnus (constellation)]]
[[Category:Sharpless objects]]
[[Category:Star-forming regions]]