The impact of the spin-orbit misalignment and of the spin of B on the Lense-Thirring orbital precessions of the double pulsar PSR J0737-3039A/B

In the double pulsar, the Lense-Thirring periastron precession omega(LT) could be used to measure/constrain the moment of inertia I-A of A. Conversely, if I-A will be independently determined with sufficient accuracy by other means, tests of the Lense-Thirring effect could be performed. Such findings rely upon a formula for omega(LT,) A induced by the spin angular momentum S-A of A, valid if the orbital angular momentum L and S-A are aligned, and neglecting omega(LT, B) because of the smallness of SB. The impact on.. LT, A of the departures of the S-A-L geometry from the ideal alignment is calculated. With the current upper bound on the misalignment angle delta(A) between them, the angles lambda(A), eta(A) of SA are constrained within 85 degrees less than or similar to lambda(A) less than or similar to 92 degrees, 266 degrees less than or similar to eta(A) less than or similar to 274 degrees. In units of the first-order post-Newtonian mass-dependent periastron precession omega(GR) = 16 degrees.89 yr(-1), a range variation Delta omega(LT, A) = omega(LT, A)(max) - omega(LT, A)(min) = 8 x 10(-8) omega(GR) is implied. The experimental uncertainty sigma(omega obs) in measuring the periastron rate should become smaller by 2028-2030. Then, the spatial orientation of S-B is constrained from the existing bounds on the misalignment angle delta(B), and omega(LT, B) similar or equal to 2 x 10(-7) omega(GR) is correspondingly calculated. The error sigma(omega obs) should become smaller around 2025. The LenseThirring inclination and node precessions. I-LT, Omega(LT) are predicted to be less than or similar to 0.05 arcsec yr(-1), far below the current experimental accuracies sigma(Iobs) = 0 degrees.5, sigma(omega obs) = 2 degrees in measuring I, Omega over 1.5 yr with the scintillation technique. The Lense-Thirring rate. x(A)(LT) of the projected semimajor axis xA of PSR J0737-3039A is less than or similar to 2 x 10(-16) s s(-1), just two orders of magnitude smaller than a putative experimental uncertainty sigma(obs)(xA) similar or equal to 10(-14) s s(-1) guessed from 2006 data.

Automated summary

This study discusses the method of using the Lense-Thirring effect to measure or constrain the moment of inertia in a double pulsar system. The research results show that the effects can be accurately tested by determining subtle variations at different scales.