Star Life Cycles 1. A star generates energy by nuclear fusion reactions in its core. The color of a star is determined by its surface temperature . (Copy this diagram).
(Copy this diagram)
Stars are classified by color and temperature. The most common system uses the letters O (blue), B(blue-white), A (white),
F (yellow-white), G (yellow),
K (orange), and M (red), from hottest to coolest.
Stars form from clouds of gas and dust called nebulas. Nebulas collapse until nuclear fusion starts.
Stars spend most of their lives on the main sequence, fusing hydrogen into helium
Sun-like stars expand into red giants, and then fade out as white dwarf stars. (draw one of these diagrams)
Very massive stars expand into red white dwarf starssupergiants, explode in supernovas and then end up as neutron stars or black holes.
(draw this diagram)