Thai telescope captures first radio signal from 12P/Pons-Brooks
NARIT’s 40-metre Thai National Radio Telescope detects hydroxyl (OH) radio signal from comet 12P/Pons-Brooks, marking a milestone for Thai astronomy.
The National Astronomical Research Institute of Thailand (NARIT) has announced the country’s first detection of radio signals from a comet using its 40-metre Thai National Radio Telescope (TNRT), a landmark achievement for Thai radio astronomy.
The study, published in The Planetary Science Journal on November 14 2025, reported that researchers detected radio emissions from hydroxyl (OH) radicals in the short-period comet 12P/Pons-Brooks, which completes an orbit around the Sun every 71 years.
When comets approach the Sun, solar radiation causes the icy nucleus to release gas and dust, forming a surrounding atmosphere known as a coma, along with dust and plasma tails. The detection of OH signals enables scientists to estimate the comet’s gas release rate—a process known as outgassing activity—which increases as the comet nears the Sun.
12P/Pons-Brooks last approached the Sun in May 22 1964 and returned in April 21 2024 after an absence of more than 70 years. NARIT’s radio astronomy team observed it on March 22, 27, and 29 2024 using the telescope’s L-band receiver.
Lead author Dr Nobuyuki Sakai said the findings were consistent with earlier research on other comets, adding that 12P/Pons-Brooks is known for sudden brightness outbursts. Future studies using the TNRT could reveal how these optical outbursts relate to the rate of OH gas production.
Located in the Huai Hong Khrai Royal Development Study Centre in Chiang Mai, the TNRT was built in collaboration with leading international institutes, including the Max Planck Institute for Radio Astronomy in Germany and the Yebes Observatory in Spain.
The project also has an international technical advisory committee featuring experts from Japan’s National Astronomical Observatory of Japan (NAOJ), Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), and China’s Shanghai Astronomical Observatory (SHAO).
The facility aims to strengthen Thailand’s research capacity in radio astronomy and its integration into global scientific networks.
The discovery marks a milestone for Thailand’s flagship astronomy facility and represents a key step in expanding the nation’s participation in international space research.
