SWEET-Cat: A catalogue of parameters for Stars With ExoplanETs

Abstract

Context. Thanks to the importance that the star-planet relation has to our understanding of the planet formation process, the precise determination of stellar parameters for the ever increasing number of discovered extra-solar planets is of great relevance. Furthermore, precise stellar parameters are needed to fully characterize the planet properties. It is thus important to continue the efforts to determine, in the most uniform way possible, the parameters for stars with planets as new discoveries are announced. Aims. In this paper we present new precise atmospheric parameters for a sample of 48 stars with planets. We then take the opportunity to present a new catalogue of stellar parameters for FGK and M stars with planets detected by radial velocity, transit, and astrometry programs. Methods. Stellar atmospheric parameters and masses for the 48 stars were derived assuming local thermodynamic equilibrium (LTE) and using high-resolution and high signal-to-noise spectra. The methodology used is based on the measurement of equivalent widths for a list of iron lines and making use of iron ionization and excitation equilibrium principles. For the catalogue, and whenever possible, we used parameters derived in previous works published by our team, using well-defined methodologies for the derivation of stellar atmospheric parameters. This set of parameters amounts to over 65% of all planet host stars known, including more than 90% of all stars with planets discovered through radial velocity surveys. For the remaining targets, stellar parameters were collected from the literature. Results. The stellar parameters for the 48 stars are presented and compared with previously determined literature values. For the catalogue, we compile values for the effective temperature, surface gravity, metallicity, and stellar mass for almost all the planet host stars listed in the Extrasolar Planets Encyclopaedia. This data will be updated on a continuous basis. The compiled catalogue is available online. The data can be used for statistical studies of the star-planet correlation, as well as for the derivation of consistent properties for known planets.

An extreme planetary system around HD 219828

“…Still according to Hipparcos, the star is stable up to 0.013 mag (typical for a constant star of its magnitude). Using a high-resolution and high signal-to-noise ratio (S/N) HARPS spectrum, Melo et al (2006) derived precise stellar atmospheric parameters for this star (see also SWEET-Cat - Santos et al 2013) 2 . The values are presented in Table 2.…”

“…A similar age was found by Casagrande et al (2011;5 ± 1.34 Gyr), also compatible with its activity level (Pace 2013, indicating an age above 2 Gyr). A mass of 1.22 M is also found using the calibration of Torres et al (2010) based on the spectroscopically derived values of T eff , log g, and [Fe/H], after correcting for the systematics as explained in Mortier et al (2014) and Santos et al (2013). We decided to adopt a value of 1.23 M to which we associated a conservative uncertainty of 0.10 M .…”

The SOPHIE search for northern extrasolar planets

“…In brief, the procedure is based on the equivalent widths of the FeI and FeII lines and the iron excitation and ionization equilibrium, which is assumed to be in local thermodynamic equilibrium. Using the derived spectroscopic parameters as input, stellar masses M were derived from the calibration of Torres et al (2010) with a correction following Santos et al (2013). Errors were computed from 10 000 random values of the stellar parameters within their error bars and assuming a Gaussian distribution.…”

Binary frequency of planet-host stars at wide separations

“…On the one hand, HD 126614 is not a main-sequence K0 star but rather a metalrich K0 sub-giant because of its temperature (5541-5645 K) and mass (1.03-1.25 M ; Howard et al 2010;Santos et al 2013). On the other hand, HD 126614 is a metal-rich star, with [Fe/H] = 0.46-0.60 (Howard et al 2010;Santos et al 2013). Hence, the above relationship for solar-type K0 main-sequence star is not applicable so we favour the Hipparcos distance.…”