POLARBEAR is a cosmic microwave background polarization experiment located in the Atacama Desert of northern Chile in the Antofagasta Region. The POLARBEAR experiment is mounted on the Huan Tran Telescope (HTT) at the James Ax Observatory in the Chajnantor Science Reserve. The HTT is located near the Atacama Cosmology Telescope on the slopes of Cerro Toco at an altitude of nearly 5,200 m (17,100 ft). 
POLARBEAR was developed by an international collaboration which includes University of California at Berkeley, Lawrence Berkeley National Lab, University of Colorado at Boulder, University of California at San Diego, Imperial College, Laboratoire Astroparticule et Cosmologie of the Paris Diderot University, KEK (High Energy Accelerator Research Organization), McGill University, and Cardiff University.
The instrument was first installed at the Combined Array for Research in Millimeter-wave Astronomy site near Westgard Pass in California (USA) for an engineering run in 2010. It was then moved to its final destination in the Atacama Desert in September 2011. POLARBEAR saw first light on January 10, 2012, and began its first observing season in April 2012.
- ^ Keating, B.; Moyerman, S.; Boettger, D.; Edwards, J.; Fuller, G.; Matsuda, F.; Miller, N.; Paar, H.; Rebeiz, G. et al. (2011). Ultra High Energy Cosmology with POLARBEAR 1110. p. 2101. arXiv:1110.2101. Bibcode:2011arXiv1110.2101K.
- ^ Lee, Adrian T.; Tran, Huan; Ade, Peter; Arnold, Kam; Borrill, Julian; Dobbs, Matt A.; Errard, Josquin; Halverson, Nils; Holzapfel, William L.; Howard, Jacob; Jaffe, Andrew; Keating, Brian; Kermish, Zigmund; Linder, Eric; Miller, Nathan; Myers, Mike; Niarchou, Anastasia; Paar, Hans; Reichardt, Christian; Spieler, Helmuth; Steinbach, Bryan; Stompor, Radek; Tucker, Carole; Quealy, Erin; Richards, Paul L.; Zahn, Oliver; Kodama, Hideo; Ioka, Kunihito (2008). "POLARBEAR: Ultra-high Energy Physics with Measurements of CMB Polarization". AIP Conference Proceedings 1040. p. 66. doi:10.1063/1.2981555.
- ^ "First Light in Chile!". University of California Berkeley Department of Physics. Retrieved 2012-03-05.