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.
Nuclear Fusion in Stars. The enormous luminous energy of the stars comes from nuclear fusion processes in their centers. Depending upon the age and mass of a star, the energy may come from proton-proton fusion, helium fusion, or the carbon cycle.