Anne Boucher is interested by the study of the atmospheres of exoplanets. At the PhD, under the supervision of David Lafrenière, her aim is to precisely determe their composition and the abundance of elements and molecules that are present. To that end, she uses the SpectroPolarimeter InfraRed SPIRou, that uses high-resolution transit spectroscopy from the ground. This instrument will see its first light in 2018 and will be the first high-resolution (= 75000) spectrograph in the infrared with such a large spectral range (0.95-2.35 um).
Transit spectroscopy is based on the following phenomenon: when a planet passes in front of its star, we see a decrease in the intensity of the received light. However, some of the light from the star passes through the atmosphere of the planet and the weak spectral signature of this atmosphere is thus imprinted in the received signal. Following a thorough analysis of this signal, we can calculate the abundance of present molecules and seek traces from biomarkers, i.e., molecules involved in basic biological reactions.
In a first place, Anne will do data simulations and to develop the tools for rapid analysis and interpretation of the SPIRou data. Then, she will observe a carefully pre-selected sample of a dozen red dwarfs. These stars, smaller than the Sun, are by far the most common stars in our galaxy and offer several observational advantages.
The presence of extraterrestrial life creates a deep curiosity among the public and in the scientific community. This project is an important step towards obtaining an answer to that question. More importantly, it will strengthen the foundations of the analysis of transit spectroscopy from the ground and in space, as with the future Thirty Meter Telescope and the James Webb Space Telescope. Thereby, we can expand our knowledge on the processes of planet formation and evolution, and eventually determine the best conditions for the development of life.
Between September 2014 and August 2016, Anne completed a Master degree, also at iREx and under the supervision of David Lafrenière, but on a different topic, the detection of debris disks around young low-mass stars by looking for an excess flux from these stars in the mid-infrared (MIR). This project led to the discovery of 4 new disks, around 3 brown dwarfs and 1 very low-mass star.
Office: Complexe des sciences, B-3435-2