View source for NGC 3766

{{Short description|Open cluster in the constellation Centaurus}}
{{Infobox open cluster
| name = NGC 3766
| image = [[File:Star cluster NGC 3766.jpg|300px]]
| caption = NGC 3766 image taken with the MPG/ESO 1.2-metre telescope at the [[La Silla Observatory]]<ref>{{cite news|title=New Kind of Variable Star Discovered|url=http://www.eso.org/public/news/eso1326/|access-date=14 June 2013|newspaper=ESO Press Release}}</ref>
| credit = [[ESO]]
| constellation = [[Centaurus]]
| epoch = [[J2000]]
| class = 
| ra = 11<sup>h</sup>&nbsp;36.1<sup>m</sup>
| dec = &minus;61° 37{{prime}}
| dist_ly = 5.5 [[lightyear|kly]]
| dist_pc = 
| appmag_v = 5.3
| size_v = 12.0{{prime}}
| mass_kg = 
| mass_msol = 
| radius_ly = 9.6 ly
| v_hb = 
| age = 
| notes = Easy to view via [[binoculars]] or [[telescope]]
| names = NGC 3766, [[Caldwell catalogue|Caldwell]] 97, [[Collinder catalogue|Collinder]] 248, [[Philibert Jacques Melotte|Melotte]] 107, Dunlop 289, Lacaille III.7, C1133-613

}}
[[File:NGC3766map.png|thumbnail|Map showing the location of NGC 3766.]]
'''NGC 3766''' (also known as '''Caldwell 97''') is an [[open cluster|open star cluster]] in the southern [[constellation]] [[Centaurus]]. It is located in the vast star-forming region known as the Carina [[molecular cloud]], and was discovered by [[Nicolas Louis de Lacaille]] during his astrometric survey in 1751–1752.<ref name=Jones_1969>{{cite journal
 | title=The search for the nebulae - VI
 | last=Jones | first=K. G.
 | journal=Journal of the British Astronomical Association
 | volume=79 | pages=213–222 | date=March 1969
 | bibcode=1969JBAA...79..213J
}}</ref> At a distance of about 1745 [[parsecs|pc]],<ref name="SIMBAD">{{cite simbad | title=NGC 3766 | access-date=2013-06-13}}</ref> the cluster subtends a diameter of about 12 [[minute of arc|minutes of arc]].<ref name="WEBDA">{{cite web | title=WEBDA Astronomical Database | work = WEBDA Page for NGC 3766 | url=http://www.univie.ac.at/webda/cgi-bin/ocl_page.cgi?cluster=ngc+3766 | access-date=2013-06-13}}</ref>

There are 137 listed stars, but many are likely non-members, with only 36 having accurate photometric data.<ref name="webda1">{{cite web | title=Webda Astronomical Database | work = WEBDA Page for NGC 3766a | url=http://www.univie.ac.at/webda/cgi-bin/frame_list.cgi?ngc3766 | access-date=2013-06-13}}</ref> It has a total [[apparent magnitude]] of 5.3 and integrated [[Stellar classification|spectral type]] of B1.7.<ref name="SIMBAD" /> NGC 3766 is relatively young, with an estimated age of log (7.160) or 14.4 million years,<ref name="WEBDA" /> and is approaching us at 14.8&nbsp;km/s.<ref name="SIMBAD" /> This cluster contains eleven [[Be star]]s, two [[red supergiant]]s and four [[Ap star]]s.<ref name="webda1" />

36 examples of an unusual type of [[variable star]] were discovered in the cluster. These fast-rotating pulsating B-type stars vary by only a few hundredths of a [[magnitude (astronomy)|magnitude]] with periods less than half a day. They are [[main sequence]] stars, hotter than [[δ Scuti variable]]s and cooler than [[slowly pulsating B star]]s.<ref name=saio>{{cite journal|doi=10.1093/mnras/stx346|arxiv=1702.02306|title=Period–luminosity relations of fast-rotating B-type stars in the young open cluster NGC 3766|journal=Monthly Notices of the Royal Astronomical Society|volume=467|issue=4|pages=3864|year=2017|last1=Saio|first1=H|last2=Ekström|first2=S|last3=Mowlavi|first3=N|last4=Georgy|first4=C|last5=Saesen|first5=S|last6=Eggenberger|first6=P|last7=Semaan|first7=T|last8=Salmon|first8=S. J. A. J|doi-access=free |bibcode=2017MNRAS.467.3864S}}</ref>

==See also==
* [[New General Catalogue]]

==References==
{{Reflist}}

==External links==
* {{commonscat-inline}}
* [http://messier.seds.org/xtra/ngc/n3766.html NGC 3766 at SEDS]
* {{usurped|1=[https://web.archive.org/web/20060820112445/http://naturespeak.com.au/LambdaCentauri.htm Astrophotograph Link]}}
* [http://www.univie.ac.at/webda/cgi-bin/frame_list.cgi?ngc3766 WEBDA Data on NGC 3766 by Lynga]
* {{WikiSky}}

{{Sky|11|36|06|-|61|37|00|5500}}
{{Catalogs|NGC=3766|C=97|Collinder=248}}
{{Ngc40}}
{{Caldwell catalogue}}
{{Centaurus}}

{{DEFAULTSORT:NGC 3766}}
[[Category:Open clusters]]
[[Category:NGC objects|3766]]
[[Category:Centaurus]]
[[Category:Caldwell objects|097b]]