DR6: LAMOST Spectra Entered the Era of Tens of Millions.

On 27 March, 2019, LAMOST released its Sixth Data Release (DR6) to both its domestic users and international partners, which includes all spectra obtained during the pilot survey and the previous six years’ regular survey. In LAMOST DR6, 4902 plates were observed and a total number of 11.26 million spectra were released, which included 9.38 million high-quality spectra with SNR ≥ 10. In addition, a catalogue which has provided stellar parameters of 6.37 million stars was also released in this data set. DR6 has resulted, up to now, in the largest public spectral set and stellar parameter catalogue worldwide. Any one that is interested in using LAMOST DR6 can log on the website at http://dr6.lamost.org/ to download this data set.

Until now, LAMOST is the first project obtaining more than 10 million spectra worldwide, which is twice the released spectra number of the other spectral survey project in the world. Exceeding10 million spectra is a landmark event for LAMOST survey. Since then, the release of LAMOST spectra has officially entered the era of tens of millions.

The huge data volume proves that LAMOST is indeed with the highest spectral acquisition rate worldwide. Fig.1 at the bottom shows the footprint of LAMOST pilot survey and the previous six years' regular survey.

The progress of LAMOST survey and scientific research results have attracted widespread concerns and interests of the international astronomical community. Until now, there are 769 LAMOST users from 124 research institutes and universities from China, the United States, Germany, Belgium and other countries to carry out scientific research, with one by one exciting achievements gradually obtained in scientific research. Up to 438 refereed papers have been published using LAMOST spectral data and 24 more are still under review. All the studies show the great advantage and potential of LAMOST to the world.

LAMOST results in a final catalogue of more than 10 million spectra after its six years' regular survey, which is an exceedingly valuable resource for a variety of astronomical fields. With the obtained data, scientists create a "digital Galaxy" for the future research on the structure, formation and evolution of Milky way and other galaxies.



Fig.1: Footprint of the LAMOST pilot survey and its previous six years’survey.(Credit: LAMOST)