View source for Southern Astrophysical Research Telescope

{{Short description|Observatory in Chile}}
{{Infobox telescope}}

The '''Southern Astrophysical Research''' ('''SOAR''') telescope is a modern {{convert|4.1|m|4=-aperture|adj=mid|sp=us}} optical and [[near-infrared]] telescope located on [[Cerro Pachón]], [[Chile]] at {{convert|2,738|m|ft}} elevation. It was commissioned in 2003, and is operated by a consortium including the countries of [[Brazil]] and [[Chile]], [[Michigan State University]], the [[Cerro Tololo Inter-American Observatory]] (CTIO) (part of the [[National Optical Astronomy Observatory]], NOAO), and the [[University of North Carolina at Chapel Hill]]. Partners have guaranteed shares varying from 10 to 30 percent of the observing time.

The telescope uses [[active optics]] on its primary and secondary mirrors to attain median image quality 0.7 arcsec at a wavelength of 500 nm. Multiple instruments are available on standby, mounted at unusually high weight-capacity [[Nasmyth telescope|Nasmyth]] foci and two lower capacity bent-[[Cassegrain reflector|Cassegrain]] foci. Switching is accomplished within a few minutes by rotating the 45° tertiary mirror. The pointing of this mirror is adjusted at high speed to prevent image blur from vibrations induced by wind-shake of the telescope structure.

== Overview ==
Its optical specifications are:
* M1 total diameter 4300mm
* Entrance Pupil Diameter	4100mm
* Pupil central Obstruction 980mm
* M1 [[F-number#Working f-number|working f/#]] 1.6855 (no prime focus is available)
* [[F-number#Working f-number|Focal plane working f/#]] 16.625
* [[Focal length#General optical systems|Effective Focal Length]] 68176.3mm
* Gamma ratio (dZ(foc)/dZ(M2))	100.5
* Zero-Vignetting Field Diameter	14.4arcmin
* Focal Plane Radius of curvature	966.3mm
* Sag w/r to Maximum Field	10.59mm<ref>{{citation|title=SOAR Telescope Official Site|url=https://noirlab.edu/science/programs/ctio/telescopes/soar-telescope}}</ref>

== Instruments ==
Current (5/2014) instruments are:
* UV–optical 16-million pixel imager (SOI, CTIO)
* near-infrared (1–2.4 μm wavelength) 1-million pixel [[HgCdTe]] imager and spectrograph (OSIRIS, Ohio State University/CTIO)
* UV–optical 16-million pixel imager and spectrograph (Goodman Spectrograph, UNC)
* near-infrared (1–2.4 μm wavelength) 16-million pixel HgCdTe imager (SPARTAN, MSU)
* adaptive optics module (SAM, CTIO)

Additional facility instruments are being commissioned:
* UV–optical 16-million pixel integral-field spectrograph (SIFS, Brazil)

User instruments are employed by individual astronomers or teams but not available to all users.

US astronomers access the telescope remotely over the [[Internet 2]]. Chilean and Brazilian astronomers use their high-speed networks. An on-site operator controls where the telescope points while the remote astronomer controls the instrument and data retrieval.

The SOAR telescope dome is a $2 million, {{convert|66|ft|m|adj=mid|-diameter}}, weatherproof structure weighing over 70 tons.<ref>{{citation
 |title       = FEA Roundup: Design, Simulation and Analysis Converge
 |journal     = Composites World
 |volume      = 4/1/2007
 |url         = http://www.compositesworld.com/articles/fea-roundup-design-simulation-and-analysis-converge.aspx
 |url-status     = dead
 |archiveurl  = https://web.archive.org/web/20081123054924/http://www.compositesworld.com/articles/fea-roundup-design-simulation-and-analysis-converge.aspx
 |archivedate = 2008-11-23
}}</ref>
== Gallery ==

<gallery mode="packed" heights="200px">
File:SOAR_Below_the_Milky_Way.jpg|{{center|SOAR Below the [[Milky Way]]}}
File:Star_Trails_over_SOAR.jpg|{{center|This image shows stars appearing to “trail” around the south celestial pole (at the center of the circles) above the Southern Astrophysical Research Telescope}}


</gallery>

== See also ==
* [[List of largest optical reflecting telescopes]]
* [[List of observatories]]

== References ==
{{Reflist}}

== External links ==
* [https://noirlab.edu/science/programs/ctio/telescopes/soar-telescope SOAR home site]
* [https://www.gov.br/lna/pt-br/composicao-1/coast/obs/soar/telescopio-soar Brazil SOAR pages]
* [https://pa.msu.edu/astro/soar-telescope.aspx MSU SOAR pages]
* [https://physics.unc.edu/research-pages/astronomy-and-astrophysics/unc-observatories/ UNC SOAR pages]
* [https://web.archive.org/web/20080723111504/http://www.nenastran.com/newnoran/chPDF/CASE_Soar_Observatory.pdf Case History - Structural Adequacy of the Dome]
* [http://www.ctio.noao.edu/noao/content/coordinates-observatories-cerro-tololo-and-cerro-pachon Coordinates for Observatories on Cerro Tololo and Cerro Pachon]

{{NOIRLab}}
{{Michigan State University}}
{{University of North Carolina at Chapel Hill}}
{{Astronomical observatories in Chile}}
{{Portal bar|Chile|Astronomy|Stars|Spaceflight|Outer space|Solar System|Education|Science|Technology}}

[[Category:Reflecting telescopes]]
[[Category:Michigan State University]]
[[Category:University of North Carolina at Chapel Hill]]
[[Category:Astronomical observatories in Chile]]
[[Category:Buildings and structures in Coquimbo Region]]
[[Category:2003 establishments in Chile]]
[[Category:NOIRLab]]