Showing papers on "Polarimetry published in 1970"

Wavelength dependence of polarization. XX - The integrated disk of the moon

Abstract: Integrated lunar disk wavelength dependence of polarization using photoelectric polarimeter, tabulating results

On polarimetry in solar active regions

Abstract: Measurements of the circular polarization V in different lines show that the deduced magnetic field strength and flux are systematically influenced by variations of the line absorption coefficient from photosphere to spot and faculae.

On polarimetry in solar active regions. ii. selection of lines interpretation of polarimetric data.

Abstract: The usefulness of magnetically sensitive iron lines Fe λ5250.2, 6173.3 and 6302.3 for solar polarimetry is investigated. The line-to-continuum absorption coefficient η0 for Fe λ5250.2 depends strongly on temperature variations. Thus a photospheric calibration of polarimeter signals cannot be used for the different parts of an active region. This is also true for the Doppler calibration of ‘longitudinal magnetographs’.Fe λ6302.5 is shown to be useful for polarimetry in active regions. A Milne-Eddington approximation is possible so that Unno's formulae are sufficient for the interpretation of polarimetric data.The ambiguity of the azimuth of the linear polarization prevents the determination of the ‘true’ field structure with respect to the solar surface. The magnetic flux cannot be determined outside the disc centre without making assumptions for the unknown field structure. This determination is possible only for single stable sunspots; for irregular active regions the field configuration remains ambiguous even at the disc centre.