Transitional pulsars.

The article focuses on the behavior and evolution of transitional millisecond pulsars (tMSPs) and related binary pulsar systems known as "spiders." It explains that pulsars in close binary systems can be spun up to millisecond rotation periods through matter transfer from a companion star, leading to changes in their emission from radio to high-energy bands during this process. The first discovered tMSP, PSR J1023+0038, has exhibited a single switch between radio and X-ray emission and has not been detected as a radio pulsar since, though it remains active in high-energy wavelengths. "Spiders" are millisecond binary pulsars with low-mass companions undergoing mass loss due to pulsar radiation, categorized as "redbacks" or "black widows" based on companion mass. Studying these systems requires coordinated observations across the electromagnetic spectrum, involving multiple telescopes, including proposals for Hubble Space Telescope campaigns.