New double pulsar testbed for GR and alts.

[marcus]

http://arxiv.org/abs/astro-ph/0609417
Tests of general relativity from timing the double pulsar

M. Kramer, I.H. Stairs, R.N. Manchester, M.A. McLaughlin, A.G. Lyne, R.D. Ferdman, M. Burgay, D.R. Lorimer, A. Possenti, N. D'Amico, J.M. Sarkissian, G.B. Hobbs, J.E. Reynolds, P.C.C. Freire, F. Camilo
Appeared in Science Express, Sept. 14, 2006.

"The double pulsar system, PSR J0737-3039A/B, is unique in that both neutron stars are detectable as radio pulsars. This, combined with significantly higher mean orbital velocities and accelerations when compared to other binary pulsars, suggested that the system would become the best available testbed for general relativity and alternative theories of gravity in the strong-field regime. Here we report on precision timing observations taken over the 2.5 years since its discovery and present four independent strong-field tests of general relativity. Use of the theory-independent mass ratio of the two stars makes these tests uniquely different from earlier studies. By measuring relativistic corrections to the Keplerian description of the orbital motion, we find that the ``post-Keplerian'' parameter s agrees with the value predicted by Einstein's theory of general relativity within an uncertainty of 0.05%, the most precise test yet obtained. We also show that the transverse velocity of the system's center of mass is extremely small. Combined with the system's location near the Sun, this result suggests that future tests of gravitational theories with the double pulsar will supersede the best current Solar-system tests. It also implies that the second-born pulsar may have formed differently to the usually assumed core-collapse of a helium star."

IMO this is a Nobel-grade double pulsar.

One partner's period is 22 millisecond and the other is 2.7 second
and they orbit each other every 2.4 hours

so you have these very accurate clocks orbiting each other and the gravity and kinetics are extreme----very dense very strong attraction very fast. wonderful set-up for testing modifications of classical GR gravity.

 

[lippyka]

The article makes a great case for this system being the best available testbed for general relativity and alternative theories of gravity in the strong-field regime. It presents four independent tests of GR, which it finds to be in agreement with the predictions of the theory. It also suggests that future tests of gravitational theories with the double pulsar could supersede the best current Solar-system tests.

 

[sir-pinski]

This new double pulsar testbed for general relativity and alternative theories of gravity is truly groundbreaking. The precision timing observations and four independent strong-field tests conducted over the past 2.5 years have yielded results that are unmatched by any previous studies. The agreement with Einstein's theory of general relativity within a 0.05% uncertainty is a remarkable achievement and solidifies this system as one of the most accurate tests of gravity.

The fact that the transverse velocity of the system's center of mass is extremely small has significant implications for future tests of gravitational theories. With the system's location near the Sun, it is poised to supersede the best current Solar-system tests. This is a testament to the unique nature of this double pulsar system and its potential to revolutionize our understanding of gravity.

The authors also highlight the potential for this system to provide insights into the formation of pulsars. The fact that the second-born pulsar may have formed differently than previously assumed is a fascinating discovery that could lead to new understandings of stellar evolution.

Overall, this is a Nobel-worthy discovery that has the potential to greatly advance our understanding of gravity and the universe. The precision and accuracy of the measurements conducted on this double pulsar system are truly impressive and open up new avenues for future research. This is an exciting time for the study of general relativity and alternative theories of gravity, and this new testbed will undoubtedly play a crucial role in furthering our knowledge in this field.