For 10 months, a SETI Institute–led team watched pulsar PSR J0332+5434 (also called B0329+54) to study how its radio signal "twinkles" as it passes through gas between the star and Earth. The team used the Allen Telescope Array (ATA) to take measurements between 900 and 1956 MHz and observed slow, significant changes in the twinkling pattern, or scintillation, over time.
Pulsars are spinning remnants of massive stars that emit flashes of radio waves, a type of light, in very precise and regular rhythms. Due to their high rotation speed and incredible density. Scientists can use sensitive radio telescopes to measure the exact times at which pulses arrive in the search for patterns that can indicate phenomena such as low-frequency gravitational waves. However, gas in interstellar space can scatter a pulsar’s radio waves—spreading them out and slightly delaying when each pulse is received. Understanding and correcting these tiny, changing delays, which can be as small as tens of nanoseconds (a nanosecond is one-billionth of a second), helps keep pulsar timing as precise as possible.
Just as starlight “twinkles” in Earth’s atmosphere, pulsar radio waves also “twinkle”, or scintillate, in space. As the signal travels through clouds of electrons between the pulsar and Earth, it creates bright and dim patches across radio frequencies. These patterns aren’t static; they evolve as the pulsar, the gas, and Earth move relative to each other. This twinkling delays the pulses, and the amount of scintillation matches the extent of the delay. By frequently monitoring a single bright, nearby pulsar, the team observed these patterns shift and translated them into tiny timing delays. These methods can then correct the delays that matter for the most precise pulsar experiments.
