Polarized light Archives

Raw B band polarization measurements of HD 189733 obtained at Gemini North on UT 1 to 7 Aug 2018, which are dominated by observations on the last night (gold points). Top left: Stokes q (linear polarization) modulation as a function of parallactic angle. Telescope linear polarization is modulated by parallactic angle with amplitude ∆(qTP, uTP) = 0.2620±0.0034% (Wiktorowicz et al. 2023), where the best fit curve from Equation 2a is shown in black. Uncertainties in most data points are smaller than the size of the data points. Top right: Same as at top left but for Stokes u (linear polarization, Equation 2b). Bottom left: Same as at top left but for Stokes v (circular polarization, Equation 2c). Bottom right: Temporal variation of parallactic angle, which rotates rapidly as the target crosses the meridian (black dashed lines) around 20:00 LST. This rapid meridian crossing provides the bulk of the telescope polarization modulation necessary for accurate calibration. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Imaging & Spectroscopy, Status Report

A Scatter of Light from a Polarized World

by Keith CowingSeptember 25, 2025

Many known exoplanets harbor clouds, which lead to degeneracies in spectroscopic models between particle composition and size. Polarimetry, however, provides independent assessment.

Selected examples of observed polarized Earthshine spectra, along with corresponding simulations of reflected and polarized light, as presented in Appendix B. For each spectrum, we include a simulated observation image, fit the power-law slopes γ, and report the RMSE between simulations and observations. -- astro-ph.EP

Astronomy & Telescopes, Atmospheres, Climate, Weather, Biogeochemical Cycles & Geobiology, Biosignatures & Paleobiology, Exoplanets, -moons, -comets, Habitable Zones, Imaging & Spectroscopy, Moon, Press Release

Planet Earth In Reflected And Polarized light – III. Modeling And Analysis Of A Decade-long Catalog Of Earthshine Observations

by Keith CowingSeptember 22, 2025September 22, 2025

Earthshine observations offer a unique opportunity to study Earth as an exoplanet seen from the Moon. As the Sun-Earth-Moon geometry changes, Earth can be observed as a spatially unresolved exoplanet […]

Polarized light

A Scatter of Light from a Polarized World

Planet Earth In Reflected And Polarized light – III. Modeling And Analysis Of A Decade-long Catalog Of Earthshine Observations

Dinosaur-killing Asteroid Also Created A Dust Cloud That Insulated Earth, Charbroiling Cretaceous Creatures

Current Water Trapping Micro-habitats On The Surface Of Mars

Methanotrophy Under Extreme Alkalinity In A Serpentinizing System

ANDES, The High-resolution Spectrograph Oof The ELT: Simulated Performance Of The CORO Module And Overview Of The High-contrast Capabilities For Exoplanet Observations

When Polymers Meet Primitive Membranes: How Molecular Cooperation May Have Helped Life Begin