[填空题]
Suppose a star the size of onu)vce /n4u4o dgldt.1 j)2dmur Sun, but with mass 8. m4e nb gt816bb9sxn5k0 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, losingbtsmb k6 g 1enbxn5984 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. $\times10^{9 }$ $rev/day$