Beatriz Pereira
Centra

Abstract
This study investigates the influence of the moonlit sky background on polarimetric astronomical observations, emphasizing its potential to contaminate data. Full Moon observations captured with
FORS2 at the ESO Paranal Observatory were analyzed to examine the polarization pattern across various wavelengths and compare it with phenomenological and theoretical single and multiple scattering models.
The results indicate that the Rayleigh scattering model generally provides a strong fit, especially when the anisotropy of molecules is accounted for by incorporating the depolarization factor. However, some discrepancies suggest the need for additional adjustments, including atmospheric influences and the effects of larger aerosol molecules. At longer wavelengths, Mie scattering, attributed to larger particles, becomes apparent. Furthermore, the Sun's contribution during twilight was observed to impact polarization. These findings underscore the importance of accounting for atmospheric factors to improve the precision of polarimetric data in astronomical studies.

2025 January 29, 13:30

IA/U.Porto
Centro de Astrofísica da Universidade do Porto (Classroom)
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