[填空题]
Suppose a star the sizur:9e 34sntofxi j :psccz60 /e of r dd4az;3)sr 7oui c*kour 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 km4z u)isda rrko37 dc*;, 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 off no angular momentum. $\times10^{9 }$ $rev/day$