{{Short description|Globular cluster in the constellation Hydra}} {{Infobox globular cluster | name = [[New General Catalogue|NGC]] 5694 | image = [[Image:NGC 5694.jpg|250px]] | caption = The core of NGC 5694 imaged by the [[Hubble Space Telescope]] | epoch = [[J2000]] | class = VII<ref name=seds /> | constellation = [[Hydra (constellation)|Hydra]] | ra = {{RA|14|39|36.5}}<ref name="simbad">{{cite simbad | title=NGC 5694 | access-date=2010-12-07}}</ref> | dec = {{DEC|-26|32|18.0}}<ref name="simbad" /> | dist_ly = 114,100ly<ref name=seds /> | appmag_v = 10.2<ref name="seds">{{cite web | work = SEDS NGC Catalog Online | title = Results for NGC 5694 | url = http://spider.seds.org/ngc/ngc.cgi?N5694 | access-date = 2010-12-07}}</ref> | size_v = 3.6{{prime}}<ref name="seds" /> | mass_kg = | mass_msol = | radius_ly = | v_hb = | metal_fe = –1.74<ref name=mnras404_3_1203/> | age = 13.44&nbsp;[[Gigayear|Gyr]]<ref name=mnras404_3_1203/> | notes = | names = [[Caldwell catalogue|Caldwell]]&nbsp;66 }} '''NGC 5694''' (also known as '''Caldwell 66''') is a [[globular cluster]] in the [[constellation]] [[Hydra (constellation)|Hydra]]. It was discovered by German-British astronomer [[William Herschel]] on 22 May 1784.{{r|selig}}

==Characteristics==

This globular cluster is located at a distance of {{convert|114000|ly|pc}} from the [[Sun]] and {{convert|96000|ly|pc}} from the [[Galactic Center]]<ref name="harris">{{cite journal| author = Harris, W.E.| year = 1996| title = A Catalog of Parameters for Globular Clusters in the Milky Way| journal = The Astronomical Journal| volume = 112| pages = 1487| url = http://physwww.physics.mcmaster.ca/%7Eharris/mwgc.dat| doi = 10.1086/118116| bibcode=1996AJ....112.1487H| url-access = subscription}}</ref> and is one of the oldest known globular clusters in the [[Milky Way Galaxy]], forming nearly 12 billion years ago.<ref name="ngc-ic-project">{{cite web |title = NGC/IC Project |work = Results for NGC 5694 |url = http://www.ngcicproject.org/ngcicdb.asp |access-date = 2010-12-07 |url-status = dead |archive-url = https://web.archive.org/web/20120520010558/http://www.ngcicproject.org/ngcicdb.asp |archive-date = 2012-05-20 }}</ref>

Its chemical composition is highly peculiar, being highly (to nearly solar levels) enriched in [[Alpha process|alpha elements]], suggesting an extragalactic origin before being captured by the Milky Way.<ref>{{citation|arxiv=1308.6653|year=2013|title=NGC 5694: Another foster son of the Galactic halo★|doi=10.1093/mnras/stt1558 |last1=Mucciarelli |first1=A. |last2=Bellazzini |first2=M. |last3=Catelan |first3=M. |last4=Dalessandro |first4=E. |last5=Amigo |first5=P. |last6=Correnti |first6=M. |last7=Cortés |first7=C. |last8=d'Orazi |first8=V. |journal=Monthly Notices of the Royal Astronomical Society |volume=435 |issue=4 |pages=3667–3680 |doi-access=free }}</ref>

==Noctua== NGC 5694 is located below the tail of the former constellation [[Noctua (constellation)|Noctua]], which included faint stars within the modern [[IAU designated constellations|IAU borders]] of Libra, Hydra, and Virgo.

==See also== *[[NGC 4372]]

==References== <references>

<ref name=mnras404_3_1203>{{citation | last1=Forbes | first1=Duncan A. | last2=Bridges | first2=Terry | title=Accreted versus in situ Milky Way globular clusters | journal=[[Monthly Notices of the Royal Astronomical Society]] | volume=404 | issue=3 | pages=1203–1214 |date=May 2010 | doi=10.1111/j.1365-2966.2010.16373.x | doi-access=free | bibcode=2010MNRAS.404.1203F | postscript=. |arxiv = 1001.4289 | s2cid=51825384 }}</ref>

<ref name=selig>{{cite web | url = https://cseligman.com/text/atlas/ngc56a.htm#5694 | title = New General Catalogue Objects: NGC 5694 | last = Seligman | first = Courtney | website = Celestial Atlas | access-date = 19 January 2026}}</ref>

Sky and Telescope June Issue, pg.66

</references>

==External links== * {{commonscat-inline}} * {{WikiSky}}

{{Sky|14|39|36.5|-|26|32|18.0|1}} {{Catalogs|C=66|NGC=5694}} {{Caldwell catalogue}} {{NGC60}} {{Hydra (constellation)}}

{{DEFAULTSORT:NGC 5694}} [[Category:Globular clusters]] [[Category:Hydra (constellation)]] [[Category:NGC objects|5694]] [[Category:Caldwell objects|066b]] [[Category:Astronomical objects discovered in 1784|17840522]]