Southern African Large Telescope

Southern African Large Telescope
Alternative namesSALT Edit this at Wikidata
Part ofSutherland observatory Edit this on Wikidata
Location(s)Sutherland, Karoo Hoogland Local Municipality, Namakwa District Municipality, Northern Cape, RSA
Coordinates32°22′33″S 20°48′39″E / 32.375918°S 20.810757°E / -32.375918; 20.810757 Edit this at Wikidata
Observatory code B31 Edit this on Wikidata
Altitude1,798 m (5,899 ft)[1]
Wavelength320 nm (940 THz)–1,700 nm (180 THz)
Built2005
Telescope styleastronomical observatory Edit this on Wikidata
Diameterhexagonal array of ~11.1 m × 9.8 m
9.2 m (effective aperture)
Angular resolutionEE(50) ≤ 0.6"
Collecting area79 m2 (91 × 0.87 m2)
66.5 m2 (effective aperture)
Mounting45 ton steel structure
Enclosure25 m spherical
Websitewww.salt.ac.za Edit this at Wikidata
Southern African Large Telescope is located in South Africa
Southern African Large Telescope
Location of Southern African Large Telescope
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The Southern African Large Telescope (SALT) is a 9.2-metre optical telescope designed mainly for spectroscopy. It consists of 91 hexagonal mirror segments each with a 1-metre inscribed diameter, resulting in a total hexagonal mirror of 11.1 by 9.8 m.[2] However, its effective aperture is only 9.2 m. It is located close to the town of Sutherland in the semi-desert region of the Karoo, South Africa. It is a facility of the South African Astronomical Observatory, the national optical observatory of South Africa.

SALT is the largest optical telescope in the southern hemisphere.[3][4] It enables spectroscopic and polarimetric analysis and imaging of the radiation from astronomical objects that are out of reach of northern hemisphere telescopes.

It is closely based on the Hobby–Eberly Telescope (HET) at McDonald Observatory, with some changes in its design, especially to the spherical aberration corrector. The main purpose for these changes was to improve the telescope's field of view. It shares the same fixed mirror altitude design, which limits access to 70% of the visible sky.[5]

First light with the full mirror was declared on 1 September 2005, with 1-arc-second resolution images of globular cluster 47 Tucanae, open cluster NGC 6152, spiral galaxy NGC 6744, and the Lagoon Nebula.[6] The official opening by President Thabo Mbeki took place during the inauguration ceremony on 10 November 2005.[7]

South Africa contributed about a third of the total of US$36 million that will finance SALT for its first 10 years (US$20 million for the construction of the telescope, US$6 million for instruments, and US$10 million for operations). The rest was contributed by the other partners: Germany, Poland, the United States, the United Kingdom, and New Zealand.[8]

  1. ^ [2013 "SALT Key Design & Performance Characteristics"]. Operational wavelengths: 320nm to 1700nm {{cite web}}: Check |url= value (help)
  2. ^ "Mirror Segments". Southern African Large Telescope website. SOAA. Retrieved 10 May 2013. The spherical primary mirror has a master radius of curvature of 26 165 mm. It consists of 91 interchangeable hexagonal mirror segments, each of 1 m inscribed diameter, forming a hexagon of ~11.1 x ~9.8 m.
  3. ^ "Deep Space Observatories: The Southern African Large Telescope". Space Today Online. Retrieved 28 January 2009.
  4. ^ "273 Precision Actuators for the Largest Telescope in the Southern Hemisphere". Physik Instrumente (PI) GmbH & Co. KG. May 2003. Retrieved 28 January 2009.
  5. ^ "Southern African Large Telescope". Armagh Observatory. Archived from the original on 6 April 2012. Retrieved 28 January 2009.
  6. ^ "S.a.l.t". May 2008.
  7. ^ "SALT Inauguration Ceremony. Address by the Honourable Minister of Science and Technology, Mr Mosibudi Mangena". South African Department of Science and Technology. 10 November 2005. Archived from the original on 25 September 2008. Retrieved 30 January 2009.
  8. ^ Kahn, Tamar (1 June 2018). "Sutherland: Wishing on a rising star".