Relative umbral intensity of a large sunspot
β Scribed by N. Mykland
- Publisher
- Springer
- Year
- 1973
- Tongue
- English
- Weight
- 593 KB
- Volume
- 28
- Category
- Article
- ISSN
- 0038-0938
No coin nor oath required. For personal study only.
π SIMILAR VOLUMES
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.
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 wave
Photo-electric observations of the intensity profile of a sunspot at a heliocentric angle of 76 ~ at four wavelengths are reported. An intensity peak at the centre-side penumbra-photosphere border predicted by Jensen et al. (1969) has been observed. Several papers have recently been published in th
A time sequence of high-resolution sunspot photographs, exposed almost simultaneously in two continuum wavelengths (4680/~ and 6400 ~), was used to study some properties of umbral fine structures ('umbral dots'). The lifetime of the umbral dots is found to be 1500 sec. Photometry of some bright dots