LAMOST Experiment for Galactic Understanding and Exploration (LEGUE) The
  survey science plan
  We describe the current plans for a spectroscopic survey of millions of stars
in the Milky Way galaxy using the Guo Shou Jing Telescope (GSJT, formerly the
Large Area Multi-Object Spectroscopic Telescope - LAMOST). The survey will
obtain spectra for 2.5 million stars brighter than $r<19$ during dark/grey
time, and 5 million stars brighter than $r<17$ or $J<16$ on nights that are
moonlit or have low transparency. The survey will begin in fall of 2012, and
will run for at least four years. The telescope design constrains the optimal
declination range for observations to $10^\circ<\delta<50^\circ$, and site
conditions lead to an emphasis on stars in the direction of the Galactic
anticenter. The survey is divided into three parts with different target
selection strategies: disk, anticenter, and spheroid. The resulting dataset
will be used to study the merger history of the Milky Way, the substructure and
evolution of the disks, the nature of the first generation of stars through
identification of the lowest metallicity stars, and star formation through
study of open clusters and the OB associations. Detailed design of the LEGUE
survey will be completed after a review of the results of the pilot survey in
summer 2012.
