[填空题]
Suppose a star the size 0bogz w+8ao6l of our Sun, but with mass 8.0 times as grecs0cy *)vv rdz 0.rh5lat, were rotating at a speed of 1.0 revolution every 12 days. If it were to undergo gravitational collapse to a neutron star of radius 11 km, losing three-quarters of its mass in the process, what would its rotation speed be? Assume that the star is a uniform sphere at all times, and that the lost mass carries cz)yl0dcr*r05.s vvh off no angular momentum. $\times10^{9 }$ $rev/day$