Red-giant branch branch (SB), and red-giant branch (RGB), for stars with different initial masses, all at solar metallicity (Z = 0.02). Also shown are the helium core mass, surface effective temperature, radius, and luminosity at the start and end of the RGB for each star. The end of the red-giant branch is defined to be when core helium ignition takes place. Intermediate-mass stars only lose a small fraction of their mass as main-sequence and subgiant stars, but lose a significant amount of mass as red giants. The mass lost by a star similar to the Sun affects the temperature and luminosity of
Sudarsky's gas giant classification to reflection by the cloud decks. At such temperatures, a gas giant may glow red from thermal radiation but the reflected light generally overwhelms thermal radiation. For stars of visual apparent magnitude under 4.50, such planets are theoretically visible to our instruments. Examples of such planets might include 51 Pegasi b and Upsilon Andromedae b. HAT-P-11b and those other extrasolar gas giants found by the Kepler telescope might be possible class V planets, such as Kepler-7b, HAT-P-7b, or Kepler-13 b. Sudarsky's gas giant classification Sudarsky's classification of gas giants for the purpose of predicting their appearance based on their temperature