Abstract

The Large sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST) has been carrying out its regular five years survey mission since September 2012, and will finish in June 2017. The novel design of LAMOST is successfully yielding a huge spectroscopic database. The LAMOST Data Release 4 (DR4) was published internally at the end of 2016, and will be internationally accessible from July 2018. The DR4 comprises a total of 3,459 plates including 7,664,073 spectra. Among those, nearly 90% are stellar objects, the others being spectra of galaxies and QSOs. Along with the spectroscopic data in fits format, DR4 also provides several catalogues which contain general information, stellar parameters, etc. This paper introduces briefly the status and progress of the LAMOST DR4, including its survey strategy, data processing and analysis pipeline, the data products and future developments.