[填空题]
Suppose a star the size ouimu hf+6v4 c3fypt/;oy dow;rue,o ;0m,7l wi our Sun, but with mass 8.0 times as great, 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 proce;t mwy 0,ywd uopor;,l;7/eioss, what would its rotation speed be? Assume that the star is a uniform sphere at all times, and that the lost mass carries off no angular momentum. $\times10^{9 }$ $rev/day$