$540, you just multiply $50 x those 6 months =$300 then you multiply $40 x those other 6 months and u get $240 and then you add the 240 and the 300 and get 540
A globular cluster is a collection of stars in the form of a sphere that orbits a galactic core. Global clusters are generally tightly bound by gravity, making the stellar density higher toward the center, and giving them their spherical shapes. Globular clusters are usually found in the halo of a galaxy.
The fact that the gravitational pull of a globular cluster is rather weak means that a single supernova explosion can blow the interstellar gas out of a globular cluster. This would mean that the gas left is not dense enough to form new stars. After the first generation, globular clusters cease to form new stars because they lack material due to their deficiency in heavy elements.
