If you fall under one of the following criteria you are eligible to sign up for Medicare: 1  People 65 years of age and older. 2  Some people with disabilities under 65 years of age. 3  People with End-Stage Renal Disease (permanent kidney failure requiring dialysis or a transplant).
Stars that are located high on the y-axis are very luminous, and have a very large diameter. This is the realm of the giants on the H-R diagram. They are massive stars, but it is their great size (some have a radius more than 1 000 times the sun's, which is appr.
Our luminous galaxy, however, appears to be embedded in a larger and much more massive, but unseen, spheroidal halo of nonluminous material. The Milky Way may actually contain as much as the mass of a trillion suns like Sol, although the 400 billion, estimated luminous stars mass only about 175 billion suns.