[填空题]
Suppose a star the size of our Sun, but w8.8sv imwtax (uqy)ohua1( x7ith mass 8.0 times a1*eazlde61*nwt- f qas 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, wha*wa6-1 znte 1 qafd*elt 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. $\times10^{9 }$ $rev/day$