A novel instrument for the advanced investigation of exoplanets

• Main Author: Clarke, N.
• Other Authors: Savini, G. ; Swinyard, B. M.
• Published: University College London (University of London) 2017
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.746380

This thesis sets out to analyse and define an instrument capable of advancing the field of exoplanet research. This exciting and nascent field of astrophysics is moving beyond simple population counts and into more detailed characterisation of exoplanet parameters. To this end high resolution and high contrast missions are required to achieve this. In this thesis three designs were investigated, two pupil masked telescopes and an interferometric system. The First masked design was an axially symmetric system using a petal mask. This design was intended to reduce the diffraction wings resulting from a circular aperture by apodising the pupil. After analysis in software it was found to be insufficient in reducing the airy rings to an acceptable level by a factor of $10^5$ and a new design was sought. Secondly a non axially symmetric mask was tried based on the spergel mask design. This displaced the light from an on axis source away from two detection zones allowing a faint off axis companion to be registered at much higher contrast. Again however the resulting contrast was insufficient to meet science goals. The third design used was an interferometer based on the Intensity Interferometer model of Hanbury Brown and Twiss. The resolution, $<0.5 mas$, and time taken per observation, $< 3600s$ for a signal to noise of 5, of a moderately sized system was found to be within reach. An attempt was made to verify this on in the laboratory. A space based mission profile that outlines this system is included.