Ground-based solar polarimetry has made great progress over the last decade. Nevertheless, polarimetry is still an afterthought in most telescope and instrument designs, and most polarimeters are designed based on experience and rules of thumb rather …
The Vector Spectromagnetograph (VSM) instrument has recorded photospheric and chromospheric magnetograms daily since August 2003. Full-disk photospheric vector magnetograms are observed at least weekly and, since November 2006, area-scans of active …
The physical characterization of exoplanets will require to take spectra at several orbital positions. For that purpose, a direct imaging capability is necessary. Direct imaging requires an efficient stellar suppression mechanism, associated with an …
The photospheric magnetic field outside of active regions and the network has a ubiquitous and dynamic line-of-sight component that strengthens from disk center to limb as expected for a nearly horizontal orientation. This component shows a striking …
The Vector SpectroMagnetograph (VSM) instrument has recorded full-disk photospheric vector magnetograms weekly since August 2003 as part of the Synoptic Optical Long-term Investigations of the Sun (SOLIS) project. After the full deployment of the VSM …
A solar photospheric ``thermal profiling`` analysis is presented, exploiting the infrared (2.3-4.6 ensuremathμm) rovibrational bands of carbon monoxide (CO) as observed with the McMath-Pierce Fourier transform spectrometer (FTS) at Kitt Peak, and …
A detailed abundance analysis is presented for solar oxygen based on the ensuremathΔV=1 fundamental (4.6åisebox-0.5ex~ensuremathμm) and ensuremathΔV=2 (2.3i̊sebox-0.5ex~ensuremathμm) first- overtone rovibrational bands of carbon monoxide observed …
SOLIS (Synoptic Optical Long-term Investigations of the Sun) is a project to replace antiquated synoptic observing equipment at the National Solar Observatory. SOLIS includes a suite of three instruments on an equatorial mount originally installed at …
Polarization modulation for solar vector polarimetry can be performed in various ways. Ferroelectric liquid crystals (FLC) have the advantage of allowing modulation frequencies of up to several kHz, therefore avoiding spurious signals due to seeing. …