The astronomical timescale based on the orbital motion of a pulsar in a binary system
Abstract
Assuming a highly deterministic pulsar's orbital motion in a close binary system, we have studied the possibility of using the orbital rotation period for establishing a new astronomical scale of the ephemeris dynamical time, which would allow the determination with high accuracy (10^1210^15) of time intervals on long time scales of the order of several tens of years. This is necessary, in particular, for searching for ultralowfrequency stochastic background of relict gravitational waves in the frequency range 10^910^12 Hz and for studying the limiting possibilities of testing alternative theories of gravity based on observations of binary pul sars. A theoretical analysis is done of the actually attainable stability of such a scale in the presence of stochastic fluctuations of pulsar pulse arrival times, which represent a mixture of `white' and `red' noise with a powerlaw dependence of the noise intensity on the Fourier frequency f^s for s = 1, 2, ..., 6. It is shown that the dynamical timescale realized in the pulsar's orbital motion proves to be more stable on long time intervals than the kinematical timescale based on the pulsar's rotation.
 Publication:

Astronomy Letters
 Pub Date:
 March 1998
 Bibcode:
 1998AstL...24..228I