Direct measurements of the optical thickness and radiative source function in the optical continuum of solar flares.
Abstract
Spectrograms of a number of white-light flares (WLFs) recently obtained at Sacramento Peak indicate that the optical continuum originates in a layer of finite optical thickness, probably elevated above the photosphere. If so, this circumstance allows the radiative source function and optical thickness of the flare layer to be measured directly, using the observed changes in the contrast of spectral features in the photospheric background as seen through the flare layer. The method is briefly described and an example of its application to the 24 April 1981 WLF is given. The effects of spatially-unresolved flare structures and of spatial/spectral non-uniformities in the background photosphere are discussed in terms of the limitations they impose on the method.
- Publication:
-
The Lower Atmosphere of Solar Flares
- Pub Date:
- 1986
- Bibcode:
- 1986lasf.conf..152N
- Keywords:
-
- Continuous Spectra;
- Light Emission;
- Optical Thickness;
- Solar Flares;
- Stellar Spectrophotometry;
- Visible Spectrum;
- Computational Astrophysics;
- Spectral Energy Distribution;
- Solar Physics;
- Solar Flares:Continuum Radiation;
- Solar Flares:Spectra;
- Spectra:Solar Flares