[填空题]
Suppose a star the size of our Sun, but with b5. xa1g;0s--k:ay o anfx k jzmngk1(nygz,/mass 8.0 times q 81xz5fwy .ndw0 lo*gctt oci;(t;i/ 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, w.ygtozx 0/oc*t5 wtd1n;i8c f qi lw;(hat 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. $\times10^{9 }$ $rev/day$