Bibcode
Sobotka, M.; Bonet, J. A.; Vazquez, M.
Bibliographical reference
Astronomy and Astrophysics (ISSN 0004-6361), vol. 260, no. 1-2, p. 437-440.
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7
1992
Citations
11
Refereed citations
9
Description
Profiles of the Na I D doublet in three bright features (clusters of
umbral dots), located in a relatively dark umbra, were analyzed by means
of the 'local two-component modeling' to obtain the 'true' continuum
intensities and temperatures of the bright features and their dark
surroundings (background). The intensities of two central and one
peripheral bright feature were 0.31 (background 0.11), 0.33 (0.13), and
0.40 (0.17), respectively. For the ratio of the object and background
intensity (assumed to be constant, but unknown until now) the value of
2.6 +/- 0.2 was obtained.