NEUTRON-STAR collisions occur inevitably when binary neutron stars spiral into each other as a result of damping of gravitational radiation. The slow neutron capture process (s-process) of nucleosynthesis is believed to occur in these stars, creating about half of the heavy elements in the universe. NEUTRON STAR ALMOST A BLACK HOLE The Schwarzschild radius for a 1.4 solar mass black hole is or 4 km. Fusion inside stars transforms hydrogen into helium, heat, and radiation. Born from the explosive death of another, larger stars, these tiny objects pack quite a punch. Neutron stars are city-size stellar objects with a mass about 1.4 times that of the sun. Neutron stars are close to being black holes.

Neutron stars are close to being black holes. NEUTRON STAR ALMOST A BLACK HOLE The Schwarzschild radius for a 1.4 solar mass black hole is or 4 km. NEUTRON-STAR collisions occur inevitably when binary neutron stars spiral into each other as a result of damping of gravitational radiation. Their escape speed is about 1/3 c and their binding energy is about 20% mc2 The average density of a neutron star, 3M/4 R3, is ~ 1015 g cm-3, greater than the density of an atomic nucleus R S= 2GM Unlike elements like carbon, silicon or iron, gold cannot be created within the core of a star. All of the atoms in the universe began as hydrogen. The other half is believed to be created by the rapid neutron capture process (r-process) of nucleosynthesis. The neutrons in a neutron star can eventually participate in nucleosynthesis. Neutron Star Mergers and Nucleosynthesis of Heavy Elements F.-K. Thielemann1;2, M. Eichler3, I.V. These neutrons are thought to bombard the surrounding atoms, rapidly producing heavy elements in what is known as r-process. Nucleosynthesis of Gold in Neutron Star Collisions Gold is rare on Earth and it is also rare in the Universe. The existence of neutron star mergers has been supported since the discovery of the binary pulsar and the observation of its orbital energy loss, consistent with General Relativity. When a binary-neutron-star system inspirals and the two neutron stars smash into each other, a shower of neutrons are released. Panov4;5, and B. Wehmeyer6 1Department of Physics, University of Basel, CH-4056 Basel, Switzerland; email: f-k.thielemann@unibas.ch 2GSI Helmholtzzentrum fur Schwerionenforschung GmbH, D-64291 Darmstadt, Germany 3Institut fur Kernphysik, Technische Universit at Darmstadt, D-64289 Abstract: The existence of neutron star mergers has been supported since the discovery of the binary pulsar and the observation of its orbital energy loss, consistent with General Relativity. Their escape speed is about 1/3 c and their binding energy is about 20% mc2 The average density of a neutron star, 3M/4 R3, is ~ 1015 g cm-3, greater than the density of an atomic nucleus RS = 2GM c2 Tidal forces during double–neutron star or neutron star/black hole mergers can pull the neutron star apart, leading to many neutron captures in a few seconds and the ejection of the processed material ( 29 ). Stellar nucleosynthesis is the process by which elements are created within stars by combining the protons and neutrons together from the nuclei of lighter elements. Such collisions will produce a characteristic burst of gravitational radiation, which may be the most promising source of a detectable signal for proposed gravity-wave detectors 1 .

nucleosynthesis.