J. P. Faria, R. D. Haywood, B. J. Brewer, P. Figueira, M. Oshagh, A. Santerne, N. C. Santos
Stellar activity can induce signals in the radial velocities of stars, complicating the detection of orbiting low-mass planets. We present a method to determine the number of planetary signals present in radial-velocity datasets of active stars, using only radial-velocity observations. Instead of considering separate fits with different number of planets, we use a birth-death Markov chain Monte Carlo algorithm to infer the posterior distribution for the number of planets in a single run. In a natural way, the marginal distributions for the orbital parameters of all planets are also inferred. This method is applied to HARPS data of CoRoT-7. We confidently recover the orbits of both CoRoT-7b and CoRoT-7c although the data show evidence for the presence of additional signals.
methods: data analysis – planetary systems – stars: individual: CoRoT-7 – techniques: radial velocities
All data and software presented in this article are available online at https://github.com/j-faria/exoBD-CoRoT7
Astronomy and Astrophysics
Volume 588, Article Number A31, Number of pages 7