The HARPS search for southern extra-solar planets. XXXVIII. Bayesian re-analysis of three systems. New super-Earths, unconfirmed signals, and magnetic cycles

Abstract

We present the analysis of the entire HARPS observations of three stars that host planetary systems: HD1461, HD40307, and HD204313. 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 $\log (R_{\mathrm{HK}}^{\prime })$ 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 HD1461 system. Four out of the six planets previously reported for HD40307 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 HD40307 g. We also fully characterise the Neptune-mass planet that orbits HD204313 in 34.9 days.

23 pages + online material, 23 figures. Accepted for publication in A&A. Small typos and series numbering corrected

References in corpus (14)

• The generalised Lomb-Scargle periodogram. A new formalism for the floating-mean and Keplerian periodograms
• Improved Age Estimation for Solar-Type Dwarfs Using Activity-Rotation Diagnostics
• Spectroscopic parameters for 451 stars in the HARPS GTO planet search program. Stellar [Fe/H] and the frequency of exo-Neptunes
• Radial velocity planets de-aliased. A new, short period for Super-Earth 55 Cnc e
• Stellar Activity Masquerading as Planets in the Habitable Zone of the M dwarf Gliese 581
• SOAP 2.0: A tool to estimate the photometric and radial velocity variations induced by stellar spots and plages
• Search for exoplanets with the radial-velocity technique: quantitative diagnostics of stellar activity
• PASTIS: Bayesian extrasolar planet validation. I. General framework, models, and performance
• Fluxes in Hαand Ca II H and K for a sample of Southern stars
• Two planets around Kapteyn's star : a cold and a temperate super-Earth orbiting the nearest halo red-dwarf
• Stellar activity mimics a habitable-zone planet around Kapteyn's star
• A Bayesian periodogram finds evidence for three planets in HD 11964
• Three Super-Earths Orbiting HD 7924
• A Third Planet Orbiting HIP 14810

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