A long-period radio transient active for three decades

Area of Science:

• Astronomy and Astrophysics
• Radio Astronomy

Background:

• Recent discoveries include long-period radio transients with polarized coherent pulses.
• These transients are sometimes attributed to magnetars, but their origins remain debated.
• Existing models struggle to explain radio emission from slowly rotating neutron stars.

Purpose of the Study:

• To investigate the nature of the newly discovered long-period radio transient GPM J1839-10.
• To search for historical data of this transient to understand its long-term behavior.
• To test the viability of current theoretical models for radio emission from celestial objects.

Main Methods:

• Observations of the radio transient GPM J1839-10 using radio telescopes.
• Analysis of pulse characteristics, including duration, brightness variation, and substructure.
• Archival radio data search to identify past occurrences of the transient.
• Calculation of the period derivative using historical data.

Main Results:

• Discovery of GPM J1839-10, a radio transient with a 21-minute period.
• Observed pulses vary in brightness by two orders of magnitude and last 30–300 seconds.
• Archival data revealed the source has been repeating since at least 1988.
• Constrained the period derivative to <3.6 × 10^-13 s s^-1.

Conclusions:

• GPM J1839-10 exhibits characteristics that challenge existing models for radio emission from neutron stars and white dwarfs.
• The long-term repeating nature and specific properties of this transient necessitate new theoretical frameworks.
• Further observations and theoretical work are required to fully understand the origin of such long-period radio transients.