Metallicity of M dwarfs

Bonfils, X.; Delfosse, X.; Udry, S.; Santos, N. C.; Forveille, T.; Ségransan, D.

doi:10.1051/0004-6361:20053046

Cited by 237 publications

(346 citation statements)

References 33 publications

(38 reference statements)

Supporting

Mentioning

331

Contrasting

Order By: Relevance

“…GJ 674's J − K color (= 0.86 -Cutri et al 2003) and the Leggett et al (2001) color-bolometric relation result in a K-band bolometric correction of BC K = 2.67, and in a 0.016 L luminosity. The K-band mass-luminosity relation of Delfosse et al (2000) gives a 0.35 M mass and the Bonfils et al (2005a) (Fig. 1).…”

Section: The Properties Of Gj 674mentioning

confidence: 87%

The HARPS search for southern extra-solar planets

Bonfils¹,

Mayor

Delfosse

et al. 2007

A&A

Self Cite

245

257

View full text Add to dashboard Cite

AstrophysicsThe HARPS search for southern extra-solar planets X. A m sin i = 11 M ⊕ planet around the nearby spotted M dwarf GJ 674 , ABSTRACTContext. How planet properties depend on stellar mass is a key diagnostic of planetary formation mechanisms. Aims. This motivates planet searches around stars that are significantly more massive or less massive than the Sun, and in particular our radial velocity search for planets around very low-mass stars. Methods. As part of that program, we obtained measurements of GJ 674, an M 2.5 dwarf at d = 4.5 pc. These measurements have dispersion much in excess of their internal errors. An intensive observing campaign demonstrates that the excess dispersion is due to two superimposed coherent signals, with periods of 4.69 and 35 days. Results. These data are described well by a 2-planet Keplerian model where each planet has a ∼11 M ⊕ minimum mass. A careful analysis of the (low-level) magnetic activity of GJ 674, however, demonstrates that the 35-day period coincides with the stellar rotation period. This signal therefore originates in a spot inhomogeneity modulated by stellar rotation. The 4.69-day signal, on the other hand, is caused by a bona-fide planet, GJ 674b. Conclusions. Its detection adds to the growing number of Neptune-mass planets around M-dwarfs and reinforces the emerging conclusion that this mass domain is much more populated than the Jovian mass range. We discuss the metallicity distributions of M dwarf with and without planets and find a low 11% probability that they are drawn from the same parent distribution. Moreover, we find tentative evidence that the host star metallicity correlates with the total mass of their planetary system.

show abstract

Section: The Properties Of Gj 674mentioning

confidence: 87%

The HARPS search for southern extra-solar planets

Bonfils¹,

Mayor

Delfosse

et al. 2007

A&A

Self Cite

245

257

View full text Add to dashboard Cite

show abstract

“…Owing to the difficulty in deriving precise values for the effective temperature and metallicity based on spectral fitting procedures (e.g. Valenti et al 1998;Woolf & Wallerstein 2005;Bean et al 2006;Önehag et al 2012), most determinations of their values are based on calibrations using colors (Bonfils et al 2005a;Johnson & Apps 2009;Casagrande et al 2008;Schlaufman & Laughlin 2010;Neves et al 2012) or spectroscopic indices (e.g. Terrien et al 2012;Rojas-Ayala et al 2012;Mann et al 2013;Neves et al 2013).…”

Section: M-dwarfs Starsmentioning

confidence: 99%

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

Santos

Sousa

Mortier

et al. 2013

A&A

Self Cite

272

250

View full text Add to dashboard Cite

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.

show abstract

“…We tested the metallicity calibration of Bonfils et al (2005) (hereafter B05), as well as the calibrations of Johnson & Apps (2009) (hereafter JA09) and Schlaufman & Laughlin (2010) (hereafter SL10), with a sample of 17 M dwarf secondaries with a wide (> 5 arcsec separation) physical FGK companion.…”

Section: Preliminary Resultsmentioning

confidence: 99%

Metallicity of M dwarfs: The link to exoplanets

Neves

Bonfils²,

Santos³

2010

Proc. IAU

Self Cite

View full text Add to dashboard Cite

Abstract. The determination of the stellar parameters of M dwarfs is of prime importance in the fields of galactic, stellar and planetary astronomy. M stars are the least studied galactic component regarding their fundamental parameters. Yet, they are the most numerous stars in the galaxy and contribute to most of its total (baryonic) mass. In particular, we are interested in their metallicity in order to study the star-planet connection and to refine the planetary parameters. As a preliminary result we present a test of the metallicity calibrations of Bonfils et al. Following B05, three papers with different calibrations were published: JA09, SL10, and Rojas-Ayala et al. (2010) (hereafter RA10). Each work claims a calibration with a better precision than the previous ones, and in general, poor V photometry is identified as a serious limitation. In order to address the photometric limitation, only M stars with precise V photometry ( σ < 0.04 mag) were selected. Most stars have V magnitude uncertainties of 0.01 or 0.02 mag. Note that the RA10 calibration was not tested because it requires IR indices that we do not have. This test will be done in the near future.We found that the metallicity values of our stars (obtained from the FGK primary component) are in reasonable agreement with the [Fe/H] values obtained with all calibrations, as can be seen in Fig. 1. However, our calibrators are found to be more metal poor (on average) than both JA09 and SL10 calibrations.A better photometry did not improve the dispersion measured around the different calibrations. This means that precision on V photometry may not be the main limitation in the derivation of the [Fe/H] calibration. Table 1. shows a quantitative comparison between the calibrations. We note that the rms, RM S P and the R 2 ap values were offset-corrected. In general, the calibrations have similar offsets, rms, RM S P , and correlation coefficients. 443at https://www.cambridge.org/core/terms. https://doi

show abstract

Metallicity of M dwarfs

Cited by 237 publications

References 33 publications

The HARPS search for southern extra-solar planets

The HARPS search for southern extra-solar planets

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

Metallicity of M dwarfs: The link to exoplanets

Contact Info

Product

Resources

About