PSR B1534+12 (J1537+1155) is a millisecond pulsar with a 37.9ms period in orbit with a neutron star companion with a 10.1 hr orbital period. This pulsar was discovered using the Arecibo 305 m radio telescope in the 430 MHz band. Timing analysis of this pulsar has produced precise measurements of five post-Keplerian parameters, making it valuable in testing gravitational theories.

We have observed PSR B1534+12 using the Five-hundred-meter Aperture Spherical radio Telescope. We found that this pulsar shows two distinct emission states: a weak state with a wide pulse profile and a burst state with a narrow pulse profile. The weak state is always present (Figure 1). We cannot, with our current data, determine whether the pulse energy of the weak state follows a normal or a log-normal distribution. The burst state energy distribution follows a power law. The amplitude of the single-pulse emission in the burst state varies significantly; the peak flux intensity of the brightest pulse is 334 times stronger than that of the average pulse. We also examined the timing precision achievable using only bright pulses, which showed no demonstrable improvement because of pulse jitter and therefore quantified the jitter noise level for this pulsar.