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The relation between the intensities of umbra and penumbra of large sunspots

✍ Scribed by G. Ekmann

Publisher
Springer
Year
1974
Tongue
English
Weight
160 KB
Volume
38
Category
Article
ISSN
0038-0938

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✦ Synopsis

Abstsact. Based on pinhole photometer observations in 4-6 wavelength regions 'gee have searched for a connection between the intensities of the umbra and the penumbra of sunspots. For the 1.67 pm wavelength region it is apparent that spots with dark umbrae also have dark penumbrae. In the other wavelength regions similar relations are found. The darkness of the spot is probably connected with the degree of complexity of the spot.

πŸ“œ SIMILAR VOLUMES

The intensity of the penumbra of large s
The intensity of the penumbra of large sunspots
✍ P. Maltby; N. Mykland πŸ“‚ Article πŸ“… 1969 πŸ› Springer 🌐 English βš– 359 KB

Simultaneous photoelectric observations of sunspot penumbrae at 5790, 6690, 8760 and 16700~ are presented. No change in penumbral intensity from spot to spot is found in a sample of 11 large sunspots.

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✍ P. N. Brandt; W. Schmidt; M. Steinegger πŸ“‚ Article πŸ“… 1990 πŸ› Springer 🌐 English βš– 232 KB

The area ratio of umbra to penumbra (Au/Ap) was investigated for a series of 126 sunspots observed around the maximum of solar activity in 1980. Plotting log (Au) as function of log (Ap) a linear relation is obtained with a slope of 1.10, yielding an average ratio Au/Ap of 0.24 for small spots and o