View source for NGC 6210

{{Short description|Planetary nebula in the constellation Hercules}}
{{Infobox nebula
| image     = [[Image:NGC 6210 HST.tif|250px]]
| caption   = A [[Hubble Space Telescope]] (HST) image of NGC 6210
| credit    = HST/[[NASA]]/[[ESA]]
| name      = [[New General Catalogue|NGC]] 6210
| epoch     = [[J2000]]
| constellation = [[Hercules (constellation)|Hercules]]
| ra        = {{RA|16|44|29.51960}}<ref name=GaiaDR2/>
| dec       = {{DEC|+23|47|59.4913}}<ref name=GaiaDR2/>
| type      = Planetary
| dist_ly   = {{convert|1.67|±|0.41|kpc|kly|adj=ri1|1|order=flip|abbr=on|lk=on}}<ref name=Bohigas2015/>
| appmag_v  =
| absmag_v  =
| appdia    =
| size_v    = {{nowrap|40″ × 30″}}<ref name=Bohigas2015/>
| radius_ly = 0.5
| notes     =
| names     = {{odlist | name=PN G043.1+37.7 | IRAS=16423+2353 | BD=+24° 3048 | NGC=6210 | HD=151121 }}<ref name=SIMBAD/>
}}
'''NGC 6210''', sometimes also known as the '''Turtle Nebula''',<ref name="interstellarum">{{cite book|last=Stoyan|first=Ronald|last2=Schurig|first2=Stephan|title=interstellarum Deep Sky Atlas|publisher=Cambridge University Press; Oculum-Verlag GmbH|publication-place=Erlangen|date=2014|isbn=978-1-107-50338-0|oclc=920437579|url=http://www.deep-sky-atlas.com/}}</ref> is a [[planetary nebula]] located  in the [[constellation]] [[Hercules (constellation)|Hercules]], approximately {{convert|1.67|±|0.41|kpc|kly|1|disp=out|abbr=on|lk=on}} from the [[Sun]].<ref name=Bohigas2015/> It is positioned about 38° above the [[galactic plane]] at a vertical distance of about {{convert|1|kpc|kly|order=flip|}} and thus has little [[Extinction (astronomy)|extinction]] from intervening [[interstellar dust]].<ref name=Pottasch2009/> This object was first recorded as a star-like feature by [[Joseph Lalande]] on March 22, 1799. However, credit for the discovery of a nebula goes to [[Wilhelm Struve]] in 1825. [[John Louis Emil Dreyer|John L. E. Dreyer]] described it as, "a planetary nebula, very bright, very small, round, disc and border".<ref name=cseligman/>
This nebula is "very amorphous and irregular" in shape, but forms a rough ellipsoid.<ref name=Pottasch2009/> It consists of two parts; a bright inner region filled with arches and filaments spanning {{nowrap|13″ × 16"}}, and a larger and fainter outer volume that has a pair of "tubular" structures. The inner region has an expansion velocity ranging over 19–24&nbsp;km/s.<ref name=Bohigas2015/> The emission from the outer part of the nebula is only about 1% of the total.<ref name=Pottasch2009/>
The central star has an [[apparent visual magnitude]] of 12.66 and the spectrum matches a [[hydrogen]]-rich star of type O(H). It has an estimated temperature of {{val|65000|u=K|fmt=commas}}. The abundances of the nebula suggest a low initial mass for the central star, probably {{val|0.9|ul=solar mass|p=~}}.<ref name=Pottasch2009/> Outflow from this star has been measured with velocities of {{val|2180|u=km/s|fmt=commas}}, and the estimated mass loss rate is {{val|2.2|e=−9|ul=solar mass}}&nbsp;yr<sup>−1</sup>. There appears to be a collaminated [[Astrophysical jet|jet]] feature to the northwest, suggesting the central star is ejecting material along two and possibly four such directions.<ref name=Phillips1996/>
==Gallery==
<gallery>
File:NGC 6210.jpg|The center of NGC 6210
</gallery>
==References==
{{reflist|refs=
<ref name=SIMBAD>{{cite simbad
| title=NGC 6210 | access-date=2020-02-26 }}</ref>
<ref name=GaiaDR2>{{Cite Gaia DR2|1299564195037054592}}</ref>
<ref name=cseligman>{{cite web
| url=https://cseligman.com/text/atlas/ngc59a.htm#5986
| title=New General Catalogue objects: NGC 6200 - 6249
| last=Seligman | first=Courtney | website=cseligman.com
| access-date=2020-09-20 }}</ref>
<ref name=Phillips1996>{{cite journal
| title=NGC 6210: an Observational Case Study of a Jet Emitting Source
| last1=Phillips | first1=J. P. | last2=Cuesta | first2=L.
| journal=Astronomical Journal
| volume=111 | page=1227 | date=March 1996
| doi=10.1086/117868 | bibcode=1996AJ....111.1227P }}</ref>
<ref name=Bohigas2015>{{cite journal
| title=Echelle spectroscopy and photoionization modelling of the entire planetary nebula NGC 6210
| last1=Bohigas | first1=J. | last2=Escalante | first2=V.
| last3=Rodríguez | first3=M. | last4=Dufour | first4=R. J.
| display-authors=1 | journal=[[Monthly Notices of the Royal Astronomical Society]]
| volume=447 | issue=1 | pages=817–835 | date=February 2015
| bibcode=2015MNRAS.447..817B  | doi=10.1093/mnras/stu2389 | doi-access=free }}</ref>
<ref name=Pottasch2009>{{cite journal
| title=Abundances in the planetary nebula NGC 6210
| display-authors=1 | last1=Pottasch | first1=S. R.
| last2=Bernard-Salas | first2=J. | last3=Roellig | first3=T. L.
| journal=[[Astronomy and Astrophysics]]
| volume=499 | issue=1 | pages=249–256 | date=May 2009
| bibcode=2009A&A...499..249P | doi=10.1051/0004-6361/200911654 | doi-access=free }}</ref>
}}
==External links==
{{commonscat}}
*[http://hubblesite.org/newscenter/archive/releases/1998/36/image/d/ '''HubbleSite NewsCenter''' Hubble picture and information on NGC 6210]
* http://freestarcharts.com/constellations?catid=7&id=1:hercules-constellation-guide
{{Ngc65}}
{{Hercules (constellation)}}
{{DEFAULTSORT:NGC 6210}}
[[Category:Planetary nebulae]]
[[Category:NGC objects|6210]]
[[Category:Hercules (constellation)]]