Context. Since 1998, a planet-search program around main sequence stars within 50 pc in the southern hemisphere has been carried out with the CORALIE echelle spectrograph at La Silla Observatory. Aims. With an observing time span of more than 14 years, the CORALIE survey is now able to unveil Jovian planets on Jupiter's period domain. This growing period-interval coverage is important for building formation and migration models since observational constraints are still weak for periods beyond the ice line. Methods. Long-term precise Doppler measurements with the CORALIE echelle spectrograph, together with a few additional observations made with the HARPS spectrograph on the ESO 3.6 m telescope, reveal radial velocity signatures of massive planetary companions on long-period orbits. Results. In this paper we present seven new planets orbiting HD 27631, HD 98649, HD 106515A, HD 166724, HD 196067, HD 219077, and HD 220689, together with the CORALIE orbital parameters for three already known planets around HD 10647, HD 30562, and HD 86226. The period range of the new planetary companions goes from 2200 to 5500 days and covers a mass domain between 1 and 10.5 M Jup . Surprisingly, five of them present very high eccentricities above e > 0.57. A pumping scenario by Kozai mechanism may be invoked for HD 106515Ab and HD 196067b, which are both orbiting stars in multiple systems. Since the presence of a third massive body cannot be inferred from the data of HD 98649b, HD 166724b, and HD 219077b, the origin of the eccentricity of these systems remains unknown. Except for HD 10647b, no constraint on the upper mass of the planets is provided by H astrometric data. Finally, the hosts of these long period planets show no metallicity excess.

The present work reports on the discovery of three stars that we have identified to be rotating Sun-like stars, based on rotational modulation signatures inferred from light curves from the CoRoT mission's Public Archives. In our analysis, we performed an initial selection based on rotation period and position in the Period-T eff diagram. This revealed that the stars CoRoT IDs 100746852, 102709980, and 105693572 provide potentially good matches to the Sun with similar rotation period. To refine our analysis, we applied a novel procedure, taking into account the fluctuations of the features associated to photometric modulation at different time intervals and the fractality traces that are present in the light curves of the Sun and of these "New Sun" candidates alike. In this sense, we computed the so-called Hurst exponent for the referred stars, for a sample of fourteen CoRoT stars with sub-and super-solar rotational periods, and for the Sun, itself, in its active and quiet phases. We found that the Hurst exponent can provide a strong discriminant of Sun-like behavior, going beyond what can be achieved with solely the rotation period itself. In particular, we find that CoRoT ID 105693572 is the star that most closely matches the solar rotation properties, as far as the latter's imprints on light curve behavior is concerned. The starsCoRoT IDs 100746852 and 102709980 have significant smaller Hurst exponents than the Sun, notwithstanding their similarity in rotation periods. (2008). Let us recall that these conclusions are based on the measurements of projected rotational velocity v sin i, which depends on the inclination angle i of the stellar rotational axis to the line of sight -which is usually unknown. In this sense, the CoRoT (Baglin 2006) and Kepler (Koch et al. 2010) space missions, offering the possibility of measuring rotation periods for thousands of stars, open a new route towards the study of the normalcy of the Sun vis-à-vis other planetary systems in the Cosmos. Several activity indicators (e.g., spots, flares) contribute to the complex temporal dynamics of stellar rotation effects. This renders light curves (hereafter LCs) extremely inhomogeneous and nonstationary, due to irregular fluctuations that are brought about by these phenomena. This also indicates that there are flutuactions acting in different scales, thus suggesting that a fractal analysis can provide a method to investigated changes in the scaling properties. solar time-series (sunspot number, sunspot area) have shown that the so-called Hurst exponent H (Hurst 1951) provides an efficient and powerful statistical method to investigate nonstationary fluctuations in solar data.Here we report on the discovery of three stars that are "New Sun" candidates, at least from the rotational point of view, based on detailed analysis of the rotational signatures obtained from LCs collected by the CoRoT space mission. In our analysis we applied a novel procedure, taking into account not only the variability of the features associated to photometric modu...

No abstract

The study of stellar parameters of planet-hosting stars, such as metallicity and chemical abundances, help us to understand the theory of planet formation and stellar evolution. Here, we present a catalogue of accurate stellar atmospheric parameters and iron abundances for a sample of 257 K and G field evolved stars that are being surveyed for planets using precise radialvelocity measurements as part of the CORALIE programme to search for planets around giants. The analysis was done using a set of high-resolution and high-signal-to-noise Ultraviolet and Visible Echelle Spectrograph spectra. The stellar parameters were derived using Fe I and II ionization and excitation equilibrium methods. To take into account possible effects related to the choice of the lines on the derived parameters, we used three different iron line-list sets in our analysis, and the results differ among themselves by a small factor for most of stars. For those stars with previous literature parameter estimates, we found very good agreement with our own values. In the present catalogue we are providing new precise spectroscopic measurements of effective temperature, surface gravity, microturbulence, and metallicity for 190 stars for which it has not been found or published in previous articles.