[填空题]
Suppose a star the sb) bo*tcriu /80idh8+ a:zc udize of our Shs nsxz0p pq. 89j(*gpun, but with mass 8.0 times as great, were rotating at a speed of 1. (gpq9 x*hpz ssj8np0.0 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. $\times10^{9 }$ $rev/day$