We present an analysis of the Rayleigh scattering in the Princeton starshade testbed and show that it explains several notable features in the contrast images. The scattering is consistent with that expected due to air molecules and does not require airborne dust to explain. Rayleigh scattering limits the observable contrast at the ~ 1 × 10^-11 level at the inner working angle in the contrast images, but it limits the observable suppression at ~ 10^-9 level. We present a crude estimate of the level of scattering of starlight to be expected in a flight starshade due to zodiacal dust in the solar system and conclude that it is unlikely to be observable. We comment on whether Rayleigh scattering drives longer starshade testbeds to operate in vacuum.

Date Published: 9 September 2019
PDF: 9 pages
Proc. SPIE 11117, Techniques and Instrumentation for Detection of Exoplanets IX, 111170M (9 September 2019); doi: 10.1117/12.2528077

Published in SPIE Proceedings Vol. 11117:
Techniques and Instrumentation for Detection of Exoplanets IX
Stuart B. Shaklan, Editor(s)