The Sun's radiation becomes linearly polarized by coherent scattering processes in the solar atmosphere. With a novel polarimetry system that achieves a precision of 1e-5 in the degree of polarization, the previously largely unexplored territory of …
The profiles of Stokes I and V of FeI 5247A, CrI 5247A, FeI 5250.2A and Fe I 5250.6A have been measured in the quiet photosphere with ZIMPOL, a new polarimeter, with very low noise level. The spatial resolution element of about 1Mm was essentially …
We have obtained images in solar coronal emission lines under high sky- background conditions by making precise differential measurements between the coronal emission line and the near-by continuum, which is primarily due to scattered light from the …
First observations of the full Stokes vector in the upper chromosphere are presented. The He I 10830 ̊A line, which has been shown to give reliable measurements of the line-of-sight component of the magnetic field vector, has been used for this …
Recent instrumental developments in imaging polarimetry allow array detectors to reach a polarimetric sensitivity of 1 × 10$^-4$ of the intensity. New instrumental effects appear at these levels of sensitivity and generate spurious polarization …
Observations of the full Stokes vector in three spectral lines indicate that flux tubes in solar plages have an average inclination in the photosphere of 14deg with respect to the local vertical. Most flux tubes are inclined in the eastwards …
The combination of the German Vacuum Tower Telescope and the prototype of ZIMPOL I (Zuerich Imaging Stokes Polarimeter I), a novel, very sensitive imaging polarimeter, has resulted in the first spectra of solar intra-network (IN) fields in circular …
Magnetic flux at the surface of the Sun is predominantly concentrated in discrete areas with kilogauss field strengths. Except for sunspots, these areas are too small to have been resolved by conventional observations. These magnetic flux tubes are …