The impact of stellar companions within the fiber in the radial velocities calculations
D. Cunha, P. Figueira, N. C. Santos, C. Lovis, G. Boué
Since the discovery by Mayor & Queloz in 1995 of the first planet orbiting another star than the Sun, the search for a planet similar to the Earth has become a priority. With the announced arrival of high precision instruments such as the ESPRESSO, we aim at achieving RV precisions better than 10 cm/s, opening the door for the detection of an Earth-mass exoplanet. For such high precision we expect that several systematic will become the limiting factor instead of the photon noise. The characterization of possible sources of noise becomes thus urgent. One possible noise source occurs with the presence of a stellar companion within the fiber. If two stars are within the fiber, the fiber will scramble the target and the stellar companion spectra, and the resulting spectra will contain the spectra of both stars. We present a study in which we characterize the impact on the radial velocity of the target induced by a stellar companion within the fiber. For this work we are using use HARPS data and transposing the result to the forthcoming ESPRESSO spectrograph. The results of the simulations will be presented and we will access the limitations induced for the detection of other Earths using present and future precise radial velocities.
17th Cambridge Workshop on Cool Stars, Stellar Systems and the Sun