China Focus: Global astronomers make discovery with sky survey telescope in China

BEIJING, Oct. 1 (Xinhua) -- A sky survey telescope installed on a mountaintop to the north of Beijing to scan celestial bodies in our Galaxy and beyond has had increasing global scientific influence over a decade after going into operation.

The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) is an ingeniously-designed instrument capable of seeing the sky wider and deeper at once. It produced the world's largest databank of stellar spectra, serving as a starry "dictionary" that global astronomers can refer to when starting a cosmic investigation.

The proportion of LAMOST-based research papers co-written by Chinese astronomers and their foreign counterparts increased from 38.9 percent in 2017 to 48.3 percent in 2021, said Zhao Yongheng, deputy director, LAMOST operation and development center.

The LAMOST survey, capable of taking 4,000 spectra in a single exposure, has released spectra for more than 10 million stars, approximately 220,000 galaxies, and some 71,000 quasars, twice as large as the spectra obtained from other ground-based sky survey telescopes put together.

Such a massive capacity makes LAMOST a facility that can partner with other telescopes globally for new insights into the universe.

A German research group relied on LAMOST observations to discover how the Milky Way took shape and evolved in its infant and juvenile stages. The results were published in the journal Nature in March.

The researchers from Max-Planck Institute for Astronomy analyzed millions of LAMOST-acquired stellar spectra and the star locations and movement provided by the European Space Agency's Gaia satellite.

"LAMOST has near-complete Gaia coverage and provides an unprecedented perspective on chemistry across the Milky Way," said a group of researchers from Columbia University and the University of Sydney who studied chemical abundances in our Galaxy.

NASA's Kepler Space Telescope is space-borne in search of planets outside our solar system. But the lack of stellar spectra of those exoplanets' host stars crippled the further closer study.

Fu Jianning, a professor of astronomy from Beijing Normal University, initiated a project linking Kepler with LAMOST.

With LAMOST spectra, the magnetic activity index of 5,648 sun-like stars found by Kepler was calculated. It revealed that twelve stars with superflares are as magnetically active as the Sun.

Also, LAMOST data have shown that most of the 698 Kepler-found exoplanets have nearly-round, coplanar orbits, demonstrating that our solar system is not unique in the Galaxy.

Zhao Gang, a researcher from the National Astronomical Observatories of the Chinese Academy of Sciences, is leading a research program collaborating with Japan's Subaru telescope to obtain high-definition spectra of poor-metal stars.

In a study published in Nature Astronomy in 2019, his team used data obtained by the two telescopes to discover a chemically peculiar star within the Galactic halo which has an unusually low amount of magnesium but contains an excessive amount of heavy elements, such as europium and uranium.

"LAMOST helped scientists achieve many unexpected findings, especially in search of peculiar celestial bodies," said Zhao Yongheng. "It has made significant contributions to the astronomic research in the world."