[填空题]
Our Sun rotates about the cvwcz tk4p2kjad)ww yc 8.n*+6enter of the Galaxy sdo1v u oa8nhq6,vf 6 i;oi;kr)mg;p, $\left(M_{G} \approx 4 \times 10^{41} \mathrm{~kg}\right)$ at a distance of about 3 $\times 10^{4}$ light-years $\left(1 \mathrm{ly}=3 \times 10^{8} \mathrm{~m} / \mathrm{s} \times 3.16 \times 10^{7} \mathrm{~s} / \mathrm{y} \times 1 y\right)$ . What is the period of our orbital motion about the center of the Galaxy? $\approx$ $\times 10^8$
