We present results based on timing of the binary millisecond pulsar J1713+0747 for 22 months through 1994 February. We have measured its annual parallax, π = (0.9 ± 0.3) mas, as well as its proper motion, μ = (6.4 ± 1.0) milliarcsec (mas) yr-1. We detect a signature in the timing residuals that is most naturally interpreted as the general relativisitic "Shapiro delay;" at the 2 σ confidence level, we find the companion mass, m2 > 0.27 M⊙, while the pulsar mass, m1 > 1.2 M⊙. Upper limits on both masses can only be obtained by imposing additional constraints on the system, such as requiring that general relativity be valid in the strongfield limit. With a post-fit weighted root mean square timing residual of approximately 0.4 μs, and a characteristic age of roughly 9 × 109 yr, this pulsar is potentially the most stable celestial clock among all known pulsars.
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science