General Relativity

and Binary Neutron Stars

A paper by:

Comm. R.M. Wey

COSR: SFS/SFC

The Collision of neutron stars marks the end of their lives and a pattern of evolution to which more than half the stars in the night sky belong. Gravitational waves given off by such stars as they orbit one another draw away energy until sufficient mass has been lost and their orbits become tighter and tighter. Finally merging with a final expulsion of radiation that can reach billions of light years out. How such phenomenon form has been a question hard put for an answer. It is an axiom that neutron stars are the remnants of once massive stellar bodies, which have come to the end of their existence in a supernova explosion. This, after first expanding to a Red giant, and then [having exhausted all its fuel] no longer able to support itself against the pull of gravity, collapses. Once a star perhaps some thousands of kilometers in diameter, now only around 15, the stars remaining mass fuses into neutrons. Leaving a very dense object of some 1.4 solar masses in an area no larger than an asteroid. But exactly what happens to binaries that both gone through a super novae explosion is not clear. Theoretically, the loss of such a large amount of the total mass should hurl both stars out into space. Yet the discovery of several binary neutron stars suggests otherwise. Research conducted has concluded that about one percent of all Binary systems survive to become Binary Neutron. And though this is only a theory, the possibility that black hole binaries exist suggests that [if so] they would number about 300 [1% of the estimated 30,000 neutron star binaries]. The very existence of such neutron binaries invoke implications not limited merely to the revision of binary stellar evolution, but to the very testing of the General Theory of Relativity itself. Though considered an axiom by some, it has truly had very few direct tests, and those conducted in rather ‘weak’ gravity. But the theory does make some rather clear predictions as to how objects will behave under such strong gravity. By measuring the Doppler effect [both first and second order] researchers were able to determine the solar masses for both objects [which matched the predictions exactly]. Historical records indicate that the first detection of bursts of high energy photons was as a result of the launching of a satellite intended to verify unauthorized detonations of nuclear warheads in space. Although the details of how [and why] colliding neutron stars give rise to the emission of gamma rays are [as yet] not fully understood, added validity of the theory of relativity is [in itself] a bonus.