What would happen to a neutron star (on the cusp of becoming a black hole) if it were sped up to near the speed of light? Or more easily done, if I sped up to near the speed of light. Would the additional mass from the near light speed cause the neutron star to collapse in on itself and form a black hole? I am guessing that a black hole would not form, but I am curious as to the reason why. If my guess is wrong and a black hole would form, then what would a person stationary to (and light hours away from) the black hole see? The stationary person would not detect an increase in mass to cause the collapse. Any insight would be appreciated.