By Joe Rao and SPACE.com

$$M(r)=\int_0^r 4\pi x^2 \rho(x) dx$$

$$\ddot{\vec{r}}=-GM(r)\frac{\vec{r}}{r^3}$$

Stars Just Got Bigger 超大质量的巨星 A 300 Solar Mass Star Uncovered 发现超过300太阳质量的蓝超巨星

Using a combination of instruments on ESO’s Very Large Telescope, astronomers have discovered the most massive stars to date, one weighing at birth more than 300 times the mass of the Sun, or twice as much as the currently accepted limit of 150 solar masses. The existence of these monsters — millions of times more luminous than the Sun, losing weight through very powerful winds — may provide an answer to the question “how massive can stars be?”

$\frac{dm(r)}{dr}=4\pi r^2 \rho(r)$————质量方程

$$m(r)=\int_0^R 4\pi r^2 \rho(r)dr$$