Polarimetry

Polarization modeling and predictions for DKIST part 2: application of the Berreman calculus to spectral polarization fringes of beamsplitters and crystal retarders

We outline polarization fringe predictions derived from an application of the Berreman calculus for the Daniel K. Inouye Solar Telescope (DKIST) retarder optics. The DKIST retarder baseline design used six crystals, single-layer antireflection …

Polarization modeling and predictions for DKIST part 2: application of the Berreman calculus to spectral polarization fringes of beamsplitters and crystal retarders

We outline polarization fringe predictions derived from a new application of the Berreman calculus for the Daniel K. Inouye Solar Telescope (DKIST) retarder optics. The DKIST retarder baseline design used 6 crystals, single layer anti-reflection …

BP Piscium: its flaring disc imaged with SPHERE/ZIMPOL$^★$

Whether BP Piscium (BP Psc) is either a pre-main sequence T Tauri star at d ensuremath≈ 80 pc, or a post-main sequence G giant at d ensuremath≈ 300 pc is still not clear. As a first-ascent giant, it is the first to be observed with a molecular and …

Direct detection of scattered light gaps in the transitional disk around HD 97048 with VLT/SPHERE

Aims: We studied the well-known circumstellar disk around the Herbig Ae/Be star HD 97048 with high angular resolution to reveal undetected structures in the disk which may be indicative of disk evolutionary processes such as planet formation. …

Multiple rings in the transition disk and companion candidates around RX J1615.3-3255. High contrast imaging with VLT/SPHERE

Context. The effects of a planet sculpting the disk from which it formed are most likely to be found in disks that are in transition between being classical protoplanetary and debris disks. Recent direct imaging of transition disks has revealed …

Design trade-off and proof of concept for LOUPE, the Lunar Observatory for Unresolved Polarimetry of Earth

We provide a proof of the technical feasibility of LOUPE, the first integral-field snapshot spectropolarimeter, designed to monitor the reflected flux and polarization spectrum of Earth. These are to be used as benchmark data for the retrieval of …

Planets and Inner Disks in Reflected Starlight with SPHERE/ZIMPOL

Improving the polarimetric sensitivity by understanding beamshifts

Mapping atmospheric aerosols with a citizen science network of smartphone spectropolarimeters

To assess the impact of atmospheric aerosols on health, climate, and air traffic, aerosol properties must be measured with fine spatial and temporal sampling. This can be achieved by actively involving citizens and the technology they own to form an …

The effects of disk and dust structure on observed polarimetric images of protoplanetary disks

Context. Imaging polarimetry is a powerful tool for imaging faint circumstellar material. It is a rapidly developing field with great promise for diagnostics of both the large-scale structures and the small-scale details of the scattering particles. …

No magnetic field in the spotted HgMn star ensuremathμ Leporis

Context. Chemically peculiar stars of the mercury-manganese (HgMn) type represent a new class of spotted late-B stars, in which evolving surface chemical inhomogeneities are apparently unrelated to the presence of strong magnetic fields but are …