View source for NGC 6755

{{Short description|Open cluster in the constellation Aquila}}
{{Infobox open cluster
 | name      = NGC 6755
 | image     = NGC_6755.png
 | caption   = NGC 6755 (taken from Stellarium)
 | credit    = <!-- Per MOS:CREDITS, credits are discouraged -->
 | epoch     = [[J2000]]
 | constellation = [[Aquila (constellation)|Aquila]]
 | ra        = {{RA|19|07|46.''1''}}<ref name=Cantat-Gaudin_Anders_2020/>
 | dec       = {{DEC|+04|13|2''6''}}<ref name=Cantat-Gaudin_Anders_2020/>
 | dist_ly   = {{cvt|2471.2|pc|ly|order=flip|lk=on}}<ref name=Cantat-Gaudin_Anders_2020/>
 | dist_pc   = 
 | appmag_v  = 7.5<ref name=O'Meara2011/>
 | size_v    = 15'<ref name=O'Meara2011/>
 | radius_ly = <!-- Radius in light years, dependent on distance -->
 | mass_msol = <!-- Cluster mass in solar masses: {{val|#.##|ul=solar mass}} -->
 | age       = 250&nbsp;Myr<ref name=Kjeldsen_Frandsen_1991/>
 | notes     = <!-- Unusual features -->
 | names     = [[New General Catalogue|NGC]] 6755, [[Collinder catalogue|Cr]] 397<ref name="simbad"/>
}}

'''NGC 6755''' is an [[open cluster]] of stars in the [[celestial equator|equatorial]] [[constellation]] of [[Aquila (constellation)|Aquila]], positioned about 3° to the east of the star [[Delta Aquilae]].<ref name=O'Meara2011/> It was discovered by the Anglo-German astronomer [[William Herschel]] on July 30, 1785<ref name=Seligman/> and is located at a distance of 8,060&nbsp;[[light year]]s from the [[Sun]].<ref name=Cantat-Gaudin_Anders_2020/> [[NGC 6756]] lies {{val|30|u=arcminute}} to the northeast of NGC 6755, with the pair forming a visual double cluster. However, they probably do not form a binary cluster system since they have different ages and are too distant from each other.<ref name=O'Meara2011/>

This cluster has a [[Trumpler class]] of II2r with a [[visual magnitude]] of 7.5 and it spans an [[angular size]] {{val|15|u=arcminute}}.<ref name=O'Meara2011/> It has an estimated age of 250&nbsp;million years, based on the [[main sequence turnoff]].<ref name=Kjeldsen_Frandsen_1991/> A total of 71 [[variable star]]s have been detected in the field of this cluster, of which 31 are [[Eclipsing binary|eclipsing binaries]], seven are [[pulsating variable]]s, and 28 are most likely [[irregular variable]] [[red giant]]s.<ref name=Ciechanowska_et_al_2007/>

==Gallery==
<gallery>
NGC 6755 map.png|Map showing location of NGC 6755 (Roberto Mura) [[File:NGC_6755_(28062025).png|thumb|348x348px|Imagen del cúmulo abierto NGC 6755 en la constelación del Águila]]
</gallery>

==References==
{{Reflist|refs=

<ref name="simbad">{{cite simbad | title = NGC 6755 | access-date=2007-04-25}}</ref>

<ref name=Seligman>{{cite web
 | title=NGC Objects: NGC 6750 - 6799
 | first=Courtney | last=Seligman
 | work=Celestial Atlas
 | url=https://cseligman.com/text/atlas/ngc67a.htm#6755
 | access-date=2022-01-07 }}</ref>

<ref name=Kjeldsen_Frandsen_1991>{{cite journal
 | title=Stellar photometric stability. II. Ages and distances for 13 open clusters with time series observations.
 | last1=Kjeldsen | first1=H. | last2=Frandsen | first2=S.
 | journal=Astronomy and Astrophysics, Supplemental Series
 | volume=87 | pages=119 | date=January 1991
 | bibcode=1991A&AS...87..119K }}</ref>

<ref name=O'Meara2011>{{cite book
 | title=Deep-Sky Companions: The Secret Deep
 | first=Stephen James | last=O'Meara | date=2011
 | volume=4 | page=371 | isbn=9780521198769
 | publisher=Cambridge University Press
 | url=https://books.google.com/books?id=v859bKO0A4gC&pg=PA371 }}</ref>

<ref name=Cantat-Gaudin_Anders_2020>{{cite journal
 | title=Clusters and mirages: cataloguing stellar aggregates in the Milky Way
 | last1=Cantat-Gaudin | first1=T. | last2=Anders | first2=F.
 | journal=Astronomy & Astrophysics
 | volume=633 | id=A99 | pages=22
 | date=January 2020 | doi=10.1051/0004-6361/201936691
 | arxiv=1911.07075 | bibcode=2020A&A...633A..99C | s2cid=208138247 }}</ref>

<ref name=Ciechanowska_et_al_2007>{{cite journal
 | title=The Optical Gravitational Lensing Experiment. Variable Stars in the Field of Open Cluster NGC 6755
 | last1=Ciechanowska | first1=A. | last2=Pietrzynski | first2=G.
 | last3=Kolaczkowski | first3=Z. | last4=Wyrzykowski | first4=L.
 | last5=Szewczyk | first5=O. | last6=Kubiak | first6=M.
 | last7=Udalski | first7=A. | last8=Szymanski | first8=M. K.
 | display-authors=1 | journal=Acta Astronomica
 | volume=57 | pages=249–266
 | date=September 2007 | bibcode=2007AcA....57..249C }}</ref>

}}

==External links==
* {{Commons category-inline}}
* {{Sky-Map.org}}

{{NGC objects:6500-6999}}
{{Aquila (constellation)}}

{{Sky|19|07|48|+|04|14|00|4632.46}}

{{DEFAULTSORT:NGC 6755}}
[[Category:Open clusters]]
[[Category:Aquila (constellation)]]
[[Category:NGC objects|6755]]


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