Research News
A Thai astronomer has contributed to the discovery of 15 pulsars
– a pathfinder for future radio surveys of neutron stars.
Tinn Thongmeearkom, a Thai astronomer at the National Astronomical Research Institute of Thailand (NARIT), together with the Transients and Pulsars with MeerKAT (TRAPUM) collaboration, used the MeerKAT radio telescope to discover 15 new pulsars. The survey began by selecting gamma-ray sources from the Fermi Gamma-ray Space Telescope. The discoveries include spider pulsars, a rare type of binary system. These findings provide opportunities for further studies in physics and pulsar evolution. In addition, the research indicates that Ultra High Frequency (UHF) is more effective than L band for detecting pulsars associated with Fermi sources, serving as a pathfinder for future pulsar surveys with large radio telescopes such as the SKA. The paper was published in the Monthly Notices of the Royal Astronomical Society on 27 February 2026.
Transients and Pulsars with MeerKAT (TRAPUM) is an international collaboration. The main goal is to find and study transients and pulsars using the MeerKAT radio telescope, operated by the South African Radio Astronomy Observatory (SARAO). MeerKAT is an array of 64 dishes, each with a diameter of 13.5 metres.
A pulsar is a fast-spinning neutron star that produces beams of electromagnetic waves that resemble those of a lighthouse. The beams are mostly observable in radio. When observed on Earth, astronomers detect a pulse-like signal. This is why it is called a “pulsar’’
The discovery begins with selecting Fermi unidentified gamma-ray sources (UnIDs) from the Fourth Fermi-LAT Source Catalogue (4FGL) produced by the Large Area Telescope (LAT) on NASA’s Fermi Gamma-ray Space Telescope. Some of these UnIDs produce pulsar-like gamma-ray spectra but have no detectable pulsations. Therefore, the radio telescope has been used to search for pulsars in these sources.
The astronomers then used the MeerKAT radio telescope, targeting 79 UnIDs and discovering 15 new pulsars. Six of these are normal pulsars, while nine are millisecond pulsars (MSPs), which can spin hundreds of times per second.
After discovering the pulsars in radio, they were timed to find their timing solutions and orbital parameters. This information was used as a starting point to search for gamma-ray pulsations using LAT data. As a result, seven of the nine MSPs were also found to emit gamma rays, confirming that these pulsars produce both radio and gamma rays. After that, joint radio and gamma-ray timing was used to study long-term orbital variations. In addition, six of the radio MSPs belong to a special type of pulsars known as “spider pulsars’’.
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Spider pulsars are MSP binary systems with a very small companion star that is being consumed or blown away by the pulsar. This behaviour resembles that of some female spiders that eat their mates. Spider pulsars can be categorised into black-widow pulsars and redback pulsars, classified by the mass of their companions. Currently, about 80 spiders have been confirmed.
Furthermore, this study compares the capabilities of UHF and L band, concluding that UHF is more effective for finding Fermi-associated pulsars. This research represents a precursor for future pulsar searches, particularly with the upcoming Square Kilometre Array (SKA) of the Square Kilometre Array Observatory (SKAO). With a total collecting area of one square kilometre. SKA will become the largest radio astronomy facility in the world.
"The discovery of 15 pulsars is just the beginning. Astronomers can use these for further study, and some systems may provide valuable information that could help reveal the mysteries of the cosmos. However, these discoveries were made possible by everyone in the Fermi Sources Working Group of TRAPUM. Thank you." said Tinn Thongmeearkom.
References:
[1] MNRAS: https://doi.org/10.1093/mnras/stag406
[2] arXiv: https://arxiv.org/abs/2602.20811