Physical conditions in the solar photosphere
Abstract
From the source-function, recently derived by SYKES, the temperature is found as a function of optical depth in the solar photosphere. The temperature distribution leads in turn to the gas pressure. To find these and other physical parameters it is necessary to assume that the photosphere is in local thermodynamic equilibrium. The uncertainty produced in these quantities by this and other assumptions, as well as by observational error, is briefly discussed. The deep layers of the photosphere, where ( d ln T/ d ln p) > 0·4, are unstable; the steep temperature gradient may arise from boundary cooling. It is shown that solar granulation probably originates in the zone of observed instability rather than in the deeper-lying hydrogen-convection zone.
- Publication:
-
Vistas in Astronomy
- Pub Date:
- 1955
- DOI:
- 10.1016/0083-6656(55)90078-7
- Bibcode:
- 1955VA......1..637P