The Korean word ‘Challan’ refers to something brilliant, radiant, or glorious, and is often used to describe dazzling light or magnificent beauty. The name reflects the instrument’s ability to capture the Sun’s radiant features.
The Challan instrument is a solar full-disk imaging spectroscopic telescope planned to be installed at three sites with a 120-degree longitudinal difference, enabling continuous 24-hour observations of the Sun. It will take data every 2.5 min with a spatial resolution of 2-3 asc and a spectral resolving power (R) of >43,000 in H alpha and Ca II 8542A bands simultaneously. Challan is composed of two modules, each dedicated to a specific waveband. This modular design is beneficial in minimizing the scattered light and simplifying the structure and engineering. The primary scientific goal of Challan is to investigate solar flares and filament eruptions. It is also expected to detect small-scale events in the solar chromosphere. In 2025, Challan will be installed at the Big Bear Solar Observatory for test observational runs, followed by scientific runs in 2026.
(See more: https://doi.org/10.48550/arXiv.2507.16294)
