Orbital Parameters of the PSR B162026 Triple System
Abstract
Previous timing data for PSR~B1620$$26 were consistent with a second companion mass $m_2$ anywhere in the range $\sim10^{3}1\,M_\odot$, i.e., from a Jupitertype planet to a star. We present the latest timing parameters for the system, including a significant change in the projected semimajor axis of the inner binary, a marginal detection of the fourth time derivative of the pulse frequency, and the pulsar proper motion (which is in agreement with published values for the proper motion of M4), and use them to further constrain the mass $m_2$ and the orbital parameters. Using the observed value of $\stackrel{\ldots.}{f}$, we obtain a oneparameter family of solutions, all with $m_2 \lo 10^{2}\,M_\odot$, i.e., excluding stellar masses. Varying $\stackrel{\ldots.}{f}$ within its formal $1\sigma$ error bar does not affect the mass range significantly. However, if we vary $\stackrel{\ldots.}{f}$ within a $4\sigma$ error bar, we find that stellarmass solutions are still possible. We also calculate the predicted rate of change of the projected semimajor axis of the inner binary and show that it agrees with the measured value.
 Publication:

IAU Colloq. 160: Pulsars: Problems and Progress
 Pub Date:
 1996
 arXiv:
 arXiv:astroph/9605141
 Bibcode:
 1996ASPC..105..525A
 Keywords:

 Astrophysics
 EPrint:
 uses PASP LaTeX macros, 6 pages, to appear in IAU Colloquium 160, Pulsars: Problems and Progress, also available from http://ensor.mit.edu/~rasio/