Bibcode
Díaz, R. F.; Ségransan, D.; Udry, S.; Lovis, C.; Pepe, F.; Dumusque, X.; Marmier, M.; Alonso, R.; Benz, W.; Bouchy, F.; Coffinet, A.; Collier Cameron, A.; Deleuil, M.; Figueira, P.; Gillon, M.; Lo Curto, G.; Mayor, M.; Mordasini, C.; Motalebi, F.; Moutou, C.; Pollacco, D.; Pompei, E.; Queloz, D.; Santos, N.; Wyttenbach, A.
Referencia bibliográfica
Astronomy and Astrophysics, Volume 585, id.A134, 24 pp.
Fecha de publicación:
1
2016
Revista
Número de citas
109
Número de citas referidas
97
Descripción
We present the analysis of the entire HARPS observations of three stars
that host planetary systems: HD 1461, HD 40307, and HD 204313. The data
set spans eight years and contains more than 200 nightly averaged
velocity measurements for each star. This means that it is sensitive to
both long-period and low-mass planets and also to the effects induced by
stellar activity cycles. We modelled the data using Keplerian functions
that correspond to planetary candidates and included the short- and
long-term effects of magnetic activity. A Bayesian approach was taken
both for the data modelling, which allowed us to include information
from activity proxies such as log R'HK in the velocity
modelling, and for the model selection, which permitted determining the
number of significant signals in the system. The Bayesian model
comparison overcomes the limitations inherent to the traditional
periodogram analysis. We report an additional super-Earth planet in the
HD 1461 system. Four out of the six planets previously reported for HD
40307 are confirmed and characterised. We discuss the remaining two
proposed signals. In particular, we show that when the systematic
uncertainty associated with the techniques for estimating model
probabilities are taken into account, the current data are not
conclusive concerning the existence of the habitable-zone candidate HD
40307 g. We also fully characterise the Neptune-mass planet that orbits
HD 204313 in 34.9 days.
Based on observations made with the HARPS instrument on the ESO 3.6 m
telescope at La Silla Observatory under the GTO programme ID 072.C-0488,
and its continuation programmes ID 183.C-0972, 091.C-0936, and
192.C-0852.Full Tables 3, 6, and 10 are only available at the CDS via
anonymous ftp to http://cdsarc.u-strasbg.fr
(ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/585/A134