The atmospheric extinction curve at Lenghu site

In this study, we use a dedicated spectroscopic telescope to carry out low-resolution measurements of the optical atmospheric extinction curve at Lenghu astronomical site in Qinghai Province, China. Observations of A0-type stars are conducted over multiple nights between 2024 and 2026, covering airmasses from 1.0 to 2.0 and wavelengths in the range of 400 to 800 nm. We derive the extinction curve for the Lenghu site and compare it with those from Mauna Kea and Cerro Paranal.