Abstract: Imaging and spectrally analyzing extrasolar planets is a very exciting approach to derive the chemical composition of their atmosphere, perform comparative exoplanetelogy, and understand the formation and evolution of the planets. However, this observing method is also very challenging as it requires observations of planetary companions that are 10^6 to 10^10 fainter than their host stars at separations shorter than 1 arcsec. In this presentation, I will briefly review the recipes to achieve exoplanet images and lift the veil on the nature of these planets. One of the main limitations is the residual speckles, the seeds of light that are left in these images of exoplanets and prevent us from observing the faintest planets. I will tell you the stories about ZELDA, our Zernike wavefront sensing approach to calibrate these errors and show some promising results on the exoplanet imager SPHERE on the VLT to push limits further for exoplanet observations.
About the speaker: Mamadou N’Diaye defended his PhD in Mexico in 2009 before doing postdocs at Laboratory of Astrophysics of Marseille in France, Space Telescope Science Institute in Baltimore. Since 2017, he has been a CNRS research staff (civil servant) working at Observatoire de la Côte d’Azur in Nice, France. His research interest is instrumentation for exoplanet imaging and spectroscopy, developing concepts in coronagraphy, wavefront sensing and control for current and future high-contrast facilities on the ground and in space.
Read More