Llano de Chajnantor Observatory

Llano de Chajnantor Observatory
Llano de Chajnantor from Cerro Toco. APEX (left) and CBI (far center) can be seen.
Organization	multiple international
Location	Atacama Desert, Chile
Coordinates	23°01′22″S 67°45′18″W / 23.02278°S 67.755°W / -23.02278; -67.755Coordinates: 23°01′22″S 67°45′18″W / 23.02278°S 67.755°W / -23.02278; -67.755
Altitude	5104 m (16,740 ft)
Weather	Driest site in the world for radio astronomy
Established	1999
Website http://www.alma.nrao.edu/development/site/
Telescopes CBI microwave ASTE submillimeter APEX submillimeter NANTEN2 millimeter-submillimeter ACT microwave QUIET microwave TAO optical-infrared ALMA millimeter-submillimeter

Llano de Chajnantor Observatory is an astronomical observatory located at an altitude of 5,104 m in the Chilean Atacama desert, 50 kilometers to the east of San Pedro de Atacama. It is a very dry site - inhospitable to humans - but an excellent site for submillimetre astronomy. Water vapour absorbs and attenuates submillimetre radiation and thus a dry site is required for this type of short-wavelength radio astronomy. It hosts some of the largest and most expensive astronomical telescopes in the world, with about 1 billion US dollars already allocated for projects on the site.

Chronology of telescopes

• 1999, Cosmic Background Imager (CBI) was the first radio telescope to start observations at Chajnantor
• 2002, Atacama Submillimeter Telescope Experiment (ASTE) installed at Pampa La Bola
• 2003, Atacama Pathfinder Experiment (APEX)
• 2004, NANTEN2 Observatory (NANTEN2)
• 2007, Atacama Cosmology Telescope (ACT)
• 2008, QUIET
• 2009, University of Tokyo Atacama Observatory (TAO)

Under construction: Atacama Large Millimeter Array (ALMA), first antennas installed in 2009

List of telescopes

Telescopes on the Llano de Chajnantor site

The Atacama Pathfinder Experiment (APEX), a new-technology 12-m telescope in operation since 2005 on Llano de Chajnantor.

• Cosmic Background Imager (CBI) - decommissioned
• Atacama Pathfinder Experiment (APEX)
• Atacama Large Millimeter Array (ALMA)
• QU Imaging Experiment (QUIET)

Telescopes on the adjacent Pampa La Bola site

• Atacama Submillimeter Telescope Experiment (ASTE)
• NANTEN2 Observatory (NANTEN2)

Telescopes on adjacent peaks

• Atacama Cosmology Telescope (ACT), on Cerro Toco
• University of Tokyo Atacama Observatory (TAO), on Cerro Chajnantor

See also

• List of highest astronomical observatories
• Purico Complex

External links

• Description of a trip to Llano de Chajnantor Observatory on BBC News