A new binary millisecond pulsar

A 4.57 ms pulsar, PSR J1713+0747, in a 67.8 day binary orbit with a low-mass (>0.28 M_⊙) companion has been detected in a systematic search of the sky at high Galactic latitudes with the Arecibo radio telescope. The new pulsar is characterized by a weak magnetic field of 1.9 × 10⁸ G and a spin-down age of 8.9 ± 1.0 Gyr, making it probably one of the oldest neutron stars currently observed. The distance to the pulsar is ∼0.8 kpc as indicated by its dispersion measure. Small timing residuals (∼ 1 μs), a relatively large flux density at GHz frequencies (S₁₄₀₀ ∼ 3 mJy), and a narrow, sharply peaked pulse morphology, make PSR J1713+0747 a new celestial clock of extraordinary precision and a rare target for VLBI frame-tie experiments.