Context: Direct imaging surveys often produce a large number of candidate companions for the observed stars, not all of which can be followed up on and confirmed or rejected as exoplanets. Aims: We...Show moreContext: Direct imaging surveys often produce a large number of candidate companions for the observed stars, not all of which can be followed up on and confirmed or rejected as exoplanets. Aims: We aim to search for archival data from the Spectro-Polarimetic High contrast imager for Exoplanets REsearch (SPHERE) and assess the nature of the candidate companions identified in the Gemini NICI Planet-Finding Campaign in 2013. Methods: We reduce the archival data from SPHERE for 10 NICI targets for which candidate companions were identified, using PynPoint. We extracted the astrometry of point sources in the images and evaluated whether these objects were consistent with either bound orbits or background trajectories. Results: We could rule out 105 out of 130 candidate companions from the NICI campaign as background contaminants. 25 remain ambiguous and 31 new candidates were discovered. Conclusions: Even though we did not detect anything, this study is still enormously important, as wide-orbit companions might be missed otherwiseShow less
To make direct detection of planets like Proxima Centauri b possible, a high contrast coronagraph with a low inner-working angle is needed. With that in mind Por et al. designed the SCAR...Show moreTo make direct detection of planets like Proxima Centauri b possible, a high contrast coronagraph with a low inner-working angle is needed. With that in mind Por et al. designed the SCAR coronagraph. In SCAR the starlight is nulled using a SCAR phase plate and a single mode multicore fiber. In this thesis we describe the process of building a spectrograph for this instrument. After a small trade-off study, we have decided to build a prism spectrograph. Due to the proximity of the fibers, resolution increases in spite of bandwidth. The ultimate design has a resolution of 110 and a bandpass from 525 to 700 nm. The spectrograph was set-up and tested using a laser and a broadband source. The design induces a lot of crosstalk, therefore we used a special extraction method for the spectra described by Bolton and Schlegel. This technique creates a 2D model of the data and extracts accordingly. Finally we have been been able to retrieve spectra using this spectrograph and extraction method. This is a proof of concept for both the SCAR and the spectrograph behind it.Show less
