Search and characterization of exoplanets by photometry: development and exploitation of the ASTEP project

• Main Author: Crouzet, Nicolas
• Other Authors: Laboratoire de Cosmologie, Astrophysique Stellaire & Solaire, de Planétologie et de Mécanique des Fluides (CASSIOPEE), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis, Tristan Guillot
• Format: Doctoral or Postdoctoral Thesis
• Language: French
• Published: HAL CCSD 2010
• Subjects: Exoplanets; Photometry; Data Analysis; ASTEP; Site testing; Antarctica; Exoplanètes; Transits; Photométrie; Observations; Analyse de données; Caractérisation de site; Dôme C; Antarctique; [SDU]Sciences of the Universe [physics]; [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]; Antarctic; The Antarctic; South Pole; Antarc*; Antarctique*; South pole
• Online Access: https://tel.archives-ouvertes.fr/tel-00553268; https://tel.archives-ouvertes.fr/tel-00553268v4/document; https://tel.archives-ouvertes.fr/tel-00553268v4/file/these_v7.pdf

The photometry of transits is a powerful method to detect and characterize exoplanets. The Concordia base in Dome C, Antarctica, is an extremely promising site for photometric astronomy due to the 3-month long night during the Antarctic winter and very favorable weather conditions. The ASTEP project (Antarctic Search for Transiting ExoPlanets) is a pilot project to discover and characterize transiting planets and understand the limits of visible photometry from the Concordia site. The project is divided into two phases : ASTEP South, a fixed 10 cm refractor, and ASTEP 400, a pointable 40 cm telescope. This thesis is dedicated to the development and exploitation of the ASTEP project. A photometric simulator is built to identify the noise sources affecting the photometry, such as seeing and PSF (Point Spread Function) variations. The simulator is used to choose the ASTEP CCD cameras. These cameras are tested and characterized. We then focus on ASTEP South. The instrument is composed of a fixed 10 cm refractor and a CCD camera inside a heated box, pointing continuously a 3.88°x3.88° field of view centered on the celestial south pole. The observation strategy is validated, and the various parts of the instrument are chosen. The observation parameters are defined from an analysis of the crowding in the field of view and tests on the sky. ASTEP South has functionned almost continuously during the 2008, 2009, and 2010 winters. A preliminary analysis leads to the qualification of Dome C for photometry : the fraction of excellent weather for photometric observations is between 56.3 and 68.4 % for the 2008 winter, and between 59.4 et 72.7 % for the 2009 winter. This is better than large observatories located in temperate sites. Lightcurves are then extracted for the 8000 stars in the field. The reduction pipeline is under improvement to reach a precision high enough to search for transit signals of exoplanets. The heart of the project, ASTEP 400, is a 40 cm telescope entirely designed and built to perform high precision ...