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.
1 A star can be luminous because it is hot or it is large, or both. 2  The luminosity of a star is its total energy output into all space over all wavelengths. 3  The star's luminosity is related to its mass. 4  The more massive a star is, the more luminous it will be.