On the morning of September 5, the first light ceremony for the Tianyu Telescope was held at the Lenghu Astronomical Observation and Research Base in Qinghai. Earlier, the Tianyu Telescope, located at the base, successfully obtained its first light image, capturing in a single exposure the North America Nebula, the Pelican Nebula in Cygnus, and over one million stars in the surrounding Milky Way, marking the completion of the telescope and its transition into the scientific observation phase.
The Tianyu Telescope is China's first 1-meter-class survey telescope with a large field of view and sub-arcsecond sampling, and serves as the pathfinder telescope for JUST (the Shanghai Jiao Tong University Spectroscopic Telescope). It was initiated in 2022, led by the Tsung-Dao Lee Institute at Shanghai Jiao Tong University, with the Shanghai Astronomical Observatory of the Chinese Academy of Sciences responsible for its development. The name "Tianyu" is derived from Professor Tsung-Dao Lee's motto, "Hear the language of the heavens to understand the way of all things"—by listening to the language of the stars, we seek to understand the truths hidden behind all phenomena.
The first light image showcases Tianyu's signature capability: its 1-meter primary mirror, paired with an internationally advanced large-format scientific camera, covers nearly 9 square degrees of the sky in a single shot—an area equivalent to more than 40 full moons. The first light image is composed of 200 stacked exposures of 0.3 seconds each, enabling the detection of celestial objects approximately one million times fainter than the limit of the human eye.
The Tianyu Project lead, Associate Professor Feng Fabo of the Tsung-Dao Lee Institute at Shanghai Jiao Tong University, noted that the Tianyu Telescope will conduct continuous photometric monitoring of hundreds of millions of celestial objects, capturing subtle brightness variations to discover exoplanets, various types of variable stars, supernovae, and small solar system bodies.
It is reported that the Tianyu Telescope and the under-construction 4-meter-class spectroscopic telescope JUST are both located at the Lenghu Astronomical Observation and Research Base in Qinghai, and are jointly operated by the JUST team at the Tsung-Dao Lee Institute. Yang Xiaohu, Project Lead of JUST and Deputy Director and Professor of the Tsung-Dao Lee Institute, explained that the Tianyu Telescope not only undertakes the scientific mission of time-domain target discovery but will also conduct engineering pre-research for JUST in areas such as observation operations and maintenance, automatic triggering of transient sources, and multi-target task scheduling, laying the hardware and software foundation for JUST to achieve first light and time-domain follow-up spectroscopic observations in 2027.
Following first light, the Tianyu Telescope will progressively transition from commissioning observations to stable observations, and from remote observations to automated observations, with scientific survey operations expected to commence in October 2026.