[填空题]
Suppose a star the size of our Sun, but ozwcx 1+.e w; zj5,tihpy/uh4with mass 8.0 time0(frdmkom1c87 .y u vds as great, were rotating adf 0d18 um( m7.vrkycot 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 off no angular momentum. $\times10^{9 }$ $rev/day$