Astrophysics Colloquium - Impact of stellar activity and flows on Earth-like planet detectability

Stellar variability strongly affects radial measurements and as a 
consequence limits the detectability and mass characterisation of low 
mass planets with radial velocity techniques. This particularly for 
long-period planets, for example in the habitable zone around solar-type 
stars, for which the planetary signal has a small amplitude. I will 
first introduce this challenge and then present a general overview of 
magnetic activity and flows at different temporal and spatial scales 
affecting radial velocities. I will then present our approach to 
characterise this impact for solar type stars, based on the very good 
knowledge of solar activity compared to other stars. After this 
overview, I will focus on three processes related to flows, 
supergranulation, meridional flows and convection inhibition.