Quote:
Originally Posted by Fred Brackin
The estimate I have for the Geminga pulsar is only 30,000 years.
Any relatively close neutron star binary ought to be a known x-ray source.
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Any rapidly rotating neutron star is a known x-ray source. Slow rotating neutron stars are almost impossible to detect if they are not consuming matter (
https://en.wikipedia.org/wiki/Neutron_star).
A plausible scenario would be a dead neutron star passes by the Sol System and runs into a rogue gas giant the size of Saturn within 1 light-year of the Earth. With the accretion causing 10% of the mass of the rogue planet to turn into gamma rays, the energy released would equal 5 * 10^42 J of energy. It is 'only' 10% of the energy of a typical GRB, but it would occur within 1 light-year of the Earth rather than within 30,000 light-years.
The Earth would receive 4 GJ of energy per square meter from the event, which would blow off the atmosphere if it happened in an instant. If it occurred over a month though, the extra flux of 1.69 kW per square meter would raise the surface temperature to uninhabitable levels, which would kill off everyone without destroying most of the infrastructure. When the accretion ended, the temperature would return to normal, though everything other than extremophiles would be dead.