Gran Telescopio Canarias

Gran Telescopio Canarias, 2008

The Gran Telescopio Canarias (GTC) ("Great Telescope Canary Islands"), sometimes called Gran TeCan, is a 10.4 m reflecting telescope and is undertaking commissioning observations at the Observatorio del Roque de los Muchachos on the island of La Palma, Spain.

The telescope is sited on a volcanic peak 2,400 metres above sea level and took 7 years to construct. The GTC Project is a partnership formed by several institutions from Spain, Mexico, and the University of Florida and an initiative from the Instituto de Astrofísica de Canarias (IAC). The construction of the telescope and its two Day One science instruments; OSIRIS and CanariCam, cost €105 million.

CanariCam

The dome of GTC under construction in 2002.

The University of Florida's CanariCam, a Day One instrument of GTC (i.e., operational from the start of observations), is a mid-infrared imager with spectroscopic, coronagraphic, and polarimetric capabilities, which will be mounted initially at the Nasmyth focus of the telescope. In the future, when the Cassegrain focus of the telescope is commissioned, it is expected that CanariCam will move to this focus, which will provide superior performance with the instrument. CanariCam is designed as a diffraction-limited imager. It is optimised as an imager, and although it will offer a range of other observing modes, these will not compromise the imaging capability. The fact that CanariCam offers polarimetry and coronagraphy in addition to the more standard imaging and spectroscopic modes makes it an extremely versatile and powerful instrument that is unique in the world. CanariCam will work in the thermal infrared between ~7.5 and 25 micrometres. At the short wavelength end the cut-off is determined by the atmosphere and specifically atmospheric water vapour. At the long wavelength end the cut-off is determined by the detector; this loses sensitivity beyond ~24 micrometres, although the cut-off for individual detectors varies significantly. CanariCam is a very compact design. It is expected that the total weight of the cryostat and its on-telescope electronics will be under 400 kg. Most previous mid-infrared instruments have used liquid helium as a cryogen. One of the requirements of CanariCam though is that it should require no expensive and difficult to handle cryogens. CanariCam will use a two-stage closed cycle cryocooler system to cool the cold optics and cryostat interior down to approximately 28 K, and the detector itself to around 8 K, the temperature at which the detector works most efficiently.

First Light

The GTC started preliminary observing on 13 July 2007 following an opening ceremony using 12 segments of its primary mirror later to be increased to a total of 36 hexagonal segments fully controlled by an active optics control system. The facility was expected to be fully operational by May 2008. Its Day One instruments are OSIRIS and CanariCam.

See also

• List of largest optical reflecting telescopes

External links

• Gran Telescopio Canarias
• GTC News
• Instituto de Astrofísica de Canarias (IAC)
• University of Florida CanariCam
• Template:Es icon Consejo Nacional de Ciencia y Tecnología de México
• Template:Es icon Instituto de Astronomía de la Universidad Nacional Autónoma de México
• CBC article — Giant Canary Islands telescope captures first light
• Images

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