Figure 19-19: R I V U X G
Analogy for Cepheid Variability (a) As pressure builds up in this pot, the force on the lid (analogous to a Cepheid’s outer layers) increases. (b) When the pressure inside the pot is sufficient, it lifts the lid off (expands the star’s outer layers) and thereby allows some of the energy inside to escape. This process goes through cycles (two are shown), as do the luminosity and temperature of Cepheid stars.
Analogy for Cepheid Variability (a) As pressure builds up in this pot, the force on the lid (analogous to a Cepheid’s outer layers) increases. (b) When the pressure inside the pot is sufficient, it lifts the lid off (expands the star’s outer layers) and thereby allows some of the energy inside to escape. This process goes through cycles (two are shown), as do the luminosity and temperature of Cepheid stars.
(Janet Horton)