Photo: Screenshot from the Science and Technology Daily wechat account

China’s Tianyu Telescope has captured more than 1 million stars in a single exposure in its first-light image, marking the completion of the telescope and its transition to the scientific observation stage, the Science and Technology Daily reported Saturday.

The first-light ceremony for the telescope was held on Saturday morning at the Lenghu Astronomical Observation and Research Base in Northwest China’s Qinghai Province, where the Tianyu Telescope is located.

The first-light image captured the North America Nebula, the Pelican Nebula and more than 1 million surrounding stars in the Milky Way in a single exposure, demonstrating the telescope’s wide-field observation capabilities, according to the report.

Tianyu is China’s first 1-meter-class survey telescope featuring a wide field of view and sub-arcsecond sampling. It is also a precursor telescope for the 4-meter-class Jiao-tong University Spectroscopic Telescope (JUST).

The telescope was launched as a project in 2022, led by the Tsung-Dao Lee Institute of Shanghai Jiao Tong University, with the Shanghai Astronomical Observatory of the Chinese Academy of Sciences responsible for its development.

Equipped with a 1-meter primary mirror and an advanced large-format scientific camera, Tianyu can cover nearly 9 square degrees of sky in a single exposure, equivalent to the area of more than 40 full moons. The first-light image was produced by stacking 200 images with 0.3-second exposures and can detect celestial objects about 1 million times fainter than the limit visible to the human eye, the report said.

Feng Fabo, an associate professor at the Tsung-Dao Lee Institute of Shanghai Jiao Tong University and project director of Tianyu, said the telescope will conduct continuous photometric monitoring of hundreds of millions of celestial objects, tracking subtle changes in their brightness to identify exoplanets, variable stars, supernovae and small bodies in the solar system, per the Science and Technology Daily. 

Tianyu and the 4-meter-class JUST telescope under construction are both located at the Lenghu Astronomical Observation and Research Base and will be operated by the JUST team. Tianyu will also support engineering trials for JUST in areas including observation operations, automatic triggering of transient sources and multi-target scheduling, according to the report.

Following first light, Tianyu will transition from commissioning observations to stable operations and from remote to automated observations. It is expected to begin scientific survey observations in October 2026.