Astronomy and Astrophysics – Astrophysics
Scientific paper
Jun 1980
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1980a%26a....86..245k&link_type=abstract
Astronomy and Astrophysics, vol. 86, no. 1-2, June 1980, p. 245-247.
Astronomy and Astrophysics
Astrophysics
34
Atmospheric Models, Calcium, Infrared Radiation, Line Spectra, Sunspots, Umbras, Gratings (Spectra), High Dispersion Spectrographs, Opacity, Photosphere, Potassium, Solar Temperature
Scientific paper
The infrared Ca(+) triplet lines at wavelengths of 8498, 8542 and 8662 A in the spectra of sunspot umbrae are investigated. Sunspot spectra were obtained in the summers of 1967, 1968 and 1978 with a plane grating spectrograph at high dispersion and a concave grating spectrograph at low dispersion, together with spectra of the neighboring photosphere. The infrared Ca(+) lines are found to be insensitive to parasitic light, while the infrared K line at 7699 A is observed to differ in the photospheric and umbral regions. Comparisons of the observed constancy of the Ca(+) line wings from photosphere to umbra with LTE calculations of current umbral models show that the umbral temperature gradient required to fit the Ca(+) triplet strongly disagrees with the observed K 7699, Na D and Fe 5434 lines, even when correcting for a maximum amount of parasitic light. The introduction of the opacity enhancement for sunspot umbrae proposed by Zwaan (1974) from considerations of continuum contrasts is found to provide a reasonable fit to all observed lines and continuum data, resulting in a model close to a scaled model of the quiet sun with an effective temperature of 4000 K.
Falipou M. A.
Kollatschny Wolfram
Stellmacher Goetz
Wiehr Eberhard
No associations
LandOfFree
The infrared Ca/+/ lines in sunspot umbrae does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with The infrared Ca/+/ lines in sunspot umbrae, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and The infrared Ca/+/ lines in sunspot umbrae will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1214305