LAMOST, Optical telescope at Xinglong Station, China

LAMOST is an optical telescope at Xinglong Station designed to observe distant stars and galaxies by collecting and analyzing their light through a specialized mirror system. The instrument works by directing light to fiber optic cables that allow simultaneous study of thousands of celestial objects in a single observation session.

Proposed by a research group led by CAS academicians Wang Shouguan and Su Dingqiang, the project was listed as a national major science project in 1996, with feasibility approval in August 1997. Construction finished on 16 October 2008 and national acceptance followed on 4 June 2009. On 17 April 2010 the telescope was formally named after the 13th-century astronomer Guo Shoujing, and the first data release came in June 2013.

The telescope was formally named the Guo Shoujing Telescope on 17 April 2010, honouring the 13th-century astronomer whose 授时历 calendar served China for centuries. Its Chinese name is 郭守敬望远镜, while LAMOST abbreviates the English title Large Sky Area Multi-Object Fiber Spectroscopic Telescope. The naming links a modern survey instrument to Yuan-dynasty astronomy.

The site lies 115 km northwest of Beijing, where atmospheric and light pollution are high and only about 120 nights a year are clear, so viewing conditions are limited. The telescope observes as objects cross the meridian, and the mirrors sit in domes at ground level while the spectrographs are housed in the tower's right-hand column.

The system employs segmented mirror technology where the main mirror is built from many small hexagonal pieces rather than a single large piece, making construction and transportation far easier. This innovative approach allows astronomers to build much larger telescopes than would otherwise be possible with solid mirrors.