Uncovering the planets and stellar activity of CoRoT-7 using only radial velocities
Abstract
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.
All data and software presented in this article are available online at https://github.com/j-faria/exoBD-CoRoT7- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- April 2016
- DOI:
- 10.1051/0004-6361/201527899
- arXiv:
- arXiv:1601.07495
- Bibcode:
- 2016A&A...588A..31F
- Keywords:
-
- methods: data analysis;
- planetary systems;
- stars: individual: CoRoT-7;
- techniques: radial velocities;
- Astrophysics - Earth and Planetary Astrophysics
- E-Print:
- 7 pages, 5 figures, 2 tables, accepted for publication in A&