China's large solar telescope ready for space weather forecasts

A Chinese large solar telescope has recently captured images of the sun's surface with details, indicating that this optical instrument can detect solar storm warnings, said scientists.

The Chinese Large Solar Telescope (CLST), with a 1.8-meter aperture, was developed by the Institute of Optics and Electronics under the auspices of the Chinese Academy of Sciences. It captured the first batch of high-resolution images of the solar atmosphere on Dec. 10, 2019.

Solar storms are the source of space weather disasters, which can lead to communication interruptions, large-scale power outages, information security accidents, and damage to spacecraft. The electromagnetic radiation, and solar proton events formed by solar storms can travel toward Earth at or near light speed.

Therefore, solar storm warnings are important to avoid damage and losses, said Rao Changhui, a lead researcher of the solar telescope project.

In late April 2020, Rao's team in Chengdu, southwest China's Sichuan Province, used the telescope to observe solar active regions and obtained more than an hour's worth of high-resolution data of the solar atmosphere.

"The 1.8-m solar telescope can discover the precursory characteristics of solar storms as early as possible, providing strong data support for solar storm warnings and solar physics research," Rao said.

According to Rao, as solar activities are increasingly frequent, space weather events will become more severe. In the future, the solar telescope, equipped with systems for magnetic field detection and velocity field detection, will make more contributions to the high-resolution detection of the solar atmosphere.

Many countries have stepped up efforts to build 2-meter and larger solar telescopes in recent years. The world's large solar telescopes include the 1.6-meter GST in the United States and the 1.5-meter GREGOR in Germany.

The U.S. 4-meter solar telescope, DKIST, has not yet been put into operation, and design and development on the European 4-meter EST has just begun.

Previous to the CLST, the largest solar telescope in China was the 1-meter New Vacuum Solar Telescope, developed by the academy's Yunnan Observatories.