Reanalysis of the radial velocities data of HD 40307 with the evidence estimator POLYCHORD

UNGER, N.; DÍAZ, R. F. ; SEGRÁNSAN, D.; DELISLE, J. -B.; HARA, N. C.

Viedma

Congreso; 61a Reunión Anual Asociación Argentina de Astronomía; 2019

We perform a reanalysis of the radial velocity data of the star HD~40307 to characterize it's planetary system. Previous works on this target differ in their results, specifically in the existence of planets e and g, with periods of 34.5 and 198~days, respectively, and minimum masses of 3.5 and 7.1~ M⊕ . For our analysis, we added new data obtained between 2015 and 2017, we made some minor modifications to the model and implemented the use of POLYCHORD, an algorithm based on Nested Sampling to estimate the Bayesian evidence. We confirm that the data does not support the existence of planet g, and we find a new ultra-short period for planet f of 0.978386 ± 1.7⋅10−5 ~days.