Abstract
Observations of the intensities of sunspot umbrae at the Oslo Solar Observatory during 5 yr are described. From the observational material we have selected measurements where the corrections for scattered light are small. The results for 5 large sunspots observed in 6 (alternatively 7) wavelength regions are presented. The observations show that possible intensity differences between individual sunspots are difficult to detect in the visible part of the spectrum. Real differences between individual sunspots are detected in the infrared region.
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References
Dicke, R. H.: 1970, Astrophys. J. 159, 25.
Eriksen, G. and Maltby, P.: 1973, Proceedings of the First Europ. Astron. Meeting, Vol. 1, 87.
Makita, M. and Morimoto, M.: 1960, Publ. Astron. Soc. Japan 12, 63.
Maltby, P.: 1970, Solar Phys. 13, 312.
Mykland, N.: 1973, Solar Phys. 28, 49.
Staveland, L.: 1972, Institute of Theoretical Astrophysics, Report No. 36.
Turon, P. J. and Lena, P. J.: 1970, Solar Phys. 14, 112.
von Klüber, H.: 1947, Z. Astrophys. 24, 121.
Zwaan, C.: 1965, Rech. Inst. Astron. Utrecht 17 (4).
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Ekmann, G., Maltby, P. Umbral intensities of large sunspots. Sol Phys 35, 317–322 (1974). https://doi.org/10.1007/BF00151952
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DOI: https://doi.org/10.1007/BF00151952