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
Red Spider Nebula complex way. The central white dwarf, the remaining compact core of the original star, produces a powerful and hot (≈10,000 K) wind blowing with a speed of 300 kilometers per second, which has generated waves 100 billion kilometres high. The waves are generated by supersonic shocks formed when the local gas is compressed and heated in front of the rapidly expanding lobes. Atoms caught in the shocks radiate a visible light. These winds are what give this nebula its unique 'spider' shape and also contribute to the expansion of the nebula. The star at the center of the Red Spider