Gran Telescopio Canarias

The Gran Telescopio Canarias (GranTeCan or GTC) is a Template:Convert reflecting telescope located at the Roque de los Muchachos Observatory on the island of La Palma, in the Canary Islands, Spain. It is the world's largest single-aperture optical telescope.<ref> Template:Cite news</ref>

Construction of the telescope took seven years and cost €130 million.<ref name=Alvarez> Template:Cite news </ref><ref name=Moreno>Template:Cite newsTemplate:Dead linkTemplate:Cbignore </ref> Its installation was hampered by weather conditions and the logistical difficulties of transporting equipment to such a remote location.<ref name=Tests/> First light was achieved in 2007 and scientific observations began in 2009.Template:Fact

The GTC Project is a partnership formed by several institutions from Spain and Mexico, the University of Florida, the National Autonomous University of Mexico,<ref>Template:Cite news</ref> and the Instituto de Astrofísica de Canarias (IAC). Planning for the construction of the telescope, which started in 1987, involved more than 1,000 people from 100 companies.<ref name=Moreno /> The division of telescope time reflects the structure of its financing: 90% Spain, 5% Mexico and 5% the University of Florida.

History

File:Grantelescopio.jpg

Dome of the GTC at sunset

First light

The GTC began its preliminary observations on 13 July 2007, using 12 segments of its primary mirror, made of Zerodur glass-ceramic by the German company Schott AG. Later, the number of segments was increased to a total of 36 hexagonal segments fully controlled by an active optics control system, working together as a reflective unit.<ref name=Tests> Template:Cite news </ref><ref>Giant telescope begins scouring space July 14, 2007 Template:Webarchive</ref> Its first instrument was the Optical System for Imaging and low Resolution Integrated Spectroscopy (OSIRIS). Scientific observations began in May 2009.<ref>Template:Cite web</ref>

Inauguration ceremony

The Gran Telescopio Canarias formally opened its shutters on July 24, 2009, inaugurated by King Juan Carlos I of Spain.<ref>Template:Cite news</ref> More than 500 astronomers, government officials and journalists from Europe and the Americas attended the ceremony. Template:Clear

Instrumentation

GTC hosts a suite of advanced instruments, including:

• OSIRIS: Optical System for Imaging and low-Intermediate-Resolution Integrated Spectroscopy The IAC's OSIRIS (Optical System for Imaging and low Resolution Integrated Spectroscopy), is an imager and spectrograph covering wavelengths from 0.365 to 1.05 μm. It has a field of view (FOV) of 7 × 7 arcmin for direct imaging, and 8 arcmin × 5.2 arcmin for low resolution spectroscopy. For spectroscopy, it offers tunable filters.<ref>Template:Cite web</ref>

• EMIR: Espectrógrafo Multiobjeto Infra-Rojo (near-infrared multi-object spectrograph)

• MEGARA: Multi-Espectrógrafo en GTC de Alta Resolución para Astronomía is an optical integral-field and multi-object spectrograph covering the visible light and near infrared wavelength range between 0.365 and 1 μm with a spectral resolution in the range R=6000–20000. The MEGARA IFU (also called the Large Compact Bundle, or LCB) offers a contiguous field of view of 12.5 arcsec x 11.3 arcsec, while the multi-object spectroscopy mode allows 92 objects to be observed simultaneously in a field of view of 3.5 arcmin x 3.5 arcmin by means of an equal number of robotic positioners. Both the LCB and MOS modes make use of 100 μm-core optical fibers (1267 in total) that are attached to a set of microlens arrays (with 623 spaxels in the case of the LCB and 92 x 7 in the case of the MOS) with each microlens covering an hexagonal region of 0.62 arcsec in diameter.<ref>Template:Cite web</ref>

• HiPERCAM: High-speed optical camera

• CanariCam: is designed as a diffraction-limited imager. It is optimized as an imager, and although it offered a range of other observing modes, these did not compromise the imaging capability. CanariCam worked in the thermal infrared between approximately 7.5 and 25 μm. At the short-wavelength end, the cut-off was determined by the atmosphere—specifically atmospheric seeing. At the long wavelength end, the cut-off was determined by the detector; this loses sensitivity beyond around 24 μm, although the cut-off for individual detectors varied significantly. CanariCam was a very compact design. It was designed for a total weight of the cryostat and its on-telescope electronics to be under 400 kg.Template:Fact Most previous mid-infrared instruments have used liquid helium as a cryogen; one of the requirements of CanariCam was that it should require no expensive and difficult to handle cryogens.Template:Fact. CanariCam used a two-stage closed cycle cryocooler system to cool the cold optics and cryostat interior to approximately Template:Convert, and the detector itself to around Template:Convert, the temperature at which the detector worked most efficiently. CanariCam was decommissioned Template:As of.<ref>Template:Cite web</ref>

See also

• Other observatory sites
  • La Silla Observatory
  • Mauna Kea Observatories
  • Paranal Observatory
• Lists and comparisons
  • Extremely large telescope
  • List of largest optical reflecting telescopes
  • List of largest optical telescopes historically

External links

• Gran Telescopio Canarias
• GTC News
• Instituto de Astrofísica de Canarias (IAC)
• University of Florida CanariCam Template:Webarchive
• Template:In lang Consejo Nacional de Ciencia y Tecnología de México
• Template:In lang Instituto de Astronomía de la Universidad Nacional Autónoma de México
• CBC article—Giant Canary Islands telescope captures first light
• Images
• Gran Telescopo Canarias inauguration press dossier (in English)
• Template:Cite web