The Color Temperature of a Sunspot Penumbra
Abstract
The new Multi-Diode Array and the recently modified Universal Birefringent Filter were used at the Vacuum Tower Telescope at the Sacramento Peak National Observatory to measure the continuum color temperature of a sunspot penumbra between 428.4 and 667.6 nm. The results show that the color temperatures within the penumbral structures closely follow a measure of the wavelength average of the brightness temperature. These observations suggest that, if the dark penumbral filaments overlie a normal quiet photosphere, they are opaque to the radiation from below.
- Publication:
-
Solar Physics
- Pub Date:
- January 1984
- DOI:
- 10.1007/BF00153779
- Bibcode:
- 1984SoPh...90....1L
- Keywords:
-
- Penumbras;
- Solar Prominences;
- Solar Spectra;
- Solar Temperature;
- Sunspots;
- Brightness Temperature;
- Continuous Spectra;
- Optical Thickness;
- Photosphere;
- Solar Instruments;
- Spectral Energy Distribution;
- Solar Physics;
- Color;
- Radiation;
- Brightness Temperature;
- Color Temperature;
- National Observatory