We have used the Zurich Imaging Stokes Polarimeter (ZIMPOL I) with the McMath-Pierce 1.5 m main telescope on Kitt Peak to obtain linear polarization measurements of the off-limb chromosphere with a sensitivity better than 1×10$^-5$. We found that the …
Spatial mapping of the Hanle and Zeeman effects on the Sun has been done for the first time, through Stokes vector imaging with a narrow- band (0.2 ̊A) universal filter. It is shown how the polarization signatures of the Hanle and Zeeman effects can …
Astronomical spectropolarimetry is performed from the X-ray to the radio regimes of the electromagnetic spectrum. The following chapter deals with instruments and their components that are used in the wavelength range from 300 nm to 20 μm. After …
To clarify the physical nature of the enigmatic scattering polarization in the Na i D$_1$ and D$_2$ line cores we have explored their behavior with full Stokes vector polarimetry in regions with varying degree of magnetic activity near the solar …
The richly structured linearly polarized spectrum that is produced by coherent scattering in the Sun's atmosphere contains a number of spectral features for which no explanation has been found within the standard scattering theory. According to this …
The remarkable polarization structure of the Na I D_1 and D_2 lines that is due to coherent scattering has remained an enigma, since it has not yet been possible to find an explanation that is consistent with both current understanding of quantum …
High-resolution observations of the full Stokes vector in FeI spectral lines around 5250 Angstroms obtained at the Swedish Vacuum Solar Telescope on La Palma with the ZIMPOL I Stokes polarimeter in a complex active region reveal the presence of …
While diagnostic techniques based on the ordinary Zeeman effect (e.g. magnetograms) are almost ``blind'' to a turbulent magnetic field with mixed magnetic polarities within the spatial resolution element, the Hanle effect is sensitive to this domain …
SOLIS (Synoptic Optical Long-term Investigations of the Sun) is a proposed suite of instruments that will modernize and greatly improve synoptic solar observations carried out by the National Solar Observatory. The primary scientific goal is to …