Abstract
The visible solar disk, or photosphere, is the external layer of the Sun where most of its light emerges from. The first section of this chapter completes the thermodynamic description of the photosphere by computing values for pressure and density in addition to the effective temperature. While the effective temperature was straightforwardly derived from the total emergent flux, the determination of pressure and density is a more complex issue. We need to both treat the ionization equilibrium of the negative hydrogen, because photoionizations of this ion are the main opacity source in the photosphere, and assess the mechanical equilibrium of the solar gas that determines the pressure and density variation with height.
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Severino, G. (2017). The Photosphere. In: The Structure and Evolution of the Sun. Undergraduate Lecture Notes in Physics. Springer, Cham. https://doi.org/10.1007/978-3-319-64961-0_3
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DOI: https://doi.org/10.1007/978-3-319-64961-0_3
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Online ISBN: 978-3-319-64961-0
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