“Tianyu” – China’s first subsecond-level sampling 1-meter-class survey telescope – achieved its first imaging, capturing over a million stars in full.

“Tianyu”, China’s first subsecond-level sampling 1-meter-class survey telescope, achieved its first imaging, capturing over one million stars in full.

China’s first subsecond-level sampling 1-meter-class survey telescope, “Tianyu,” successfully captured the first light image at the Qinghai Cold Lake Astronomical Observation and Research Base. In a single exposure, it captured over one million stars. Developed under the leadership of the Lee Teng-hui Institute at Shanghai Jiao Tong University, this telescope has a primary mirror diameter of 1 meter. A single shot covers nearly 9 square degrees of the sky, enabling it to detect celestial objects about a million times darker than the limit of the human eye. The first-light image was created by combining 200 images exposed for 0.3 seconds each. In the future, “Tianyu” will conduct continuous photometric monitoring of hundreds of millions of celestial objects, detecting subtle changes in brightness to identify targets such as exoplanets, variable stars, and supernovae outside the solar system. As a precursor to the 4-meter-class spectroscopy telescope JUST under construction, “Tianyu” will carry out time-domain target discovery missions and provide engineering pre-research support for JUST in terms of observation operations and automatic triggering of transient sources, helping JUST to achieve its first light by 2027. It is expected that “Tianyu” will start scientific survey operations in October 2026.