[填空题]
Suppose a star the size of our S,ibf o9*0stqo-pt75 aqd ig* kun, but y 6dyfiuo;q-8 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 process, what would itsf6;8 qoyd i-uy rotation speed be? Assume that the star is a uniform sphere at all times, and that the lost mass carries off no angular momentum. $\times10^{9 }$ $rev/day$