CARMENES input catalogue of M dwarfs

Abstract

Context. The relevance of M dwarfs in the search for potentially habitable Earth-sized planets has grown significantly in the last years. Aims. In our on-going effort to comprehensively and accurately characterise confirmed and potential planet-hosting M dwarfs, in particular for the CARMENES survey, we have carried out a comprehensive multi-band photometric analysis involving spectral energy distributions, luminosities, absolute magnitudes, colours, and spectral types, from which we have derived basic astrophysical parameters. Methods. We have carefully compiled photometry in 20 passbands from the ultraviolet to the mid-infrared, and combined it with the latest parallactic distances and close-multiplicity information, mostly from Gaia DR2, of a sample of 2479 K5 V to L8 stars and ultracool dwarfs, including 2210 nearby, bright M dwarfs. For this, we made extensive use of Virtual Observatory tools. Results. We have homogeneously computed accurate bolometric luminosities and effective temperatures of 1843 single stars, derived their radii and masses, studied the impact of metallicity, and compared our results with the literature. The over 40 000 individually inspected magnitudes, together with the basic data and derived parameters of the stars, individual and averaged by spectral type, have been made public to the astronomical community. In addition, we have reported 40 new close multiple systems and candidates (ρ < 3.3 arcsec) and 36 overluminous stars that are assigned to young Galactic populations. Conclusions. In the new era of exoplanet searches around M dwarfs via transit (e.g. TESS, PLATO) and radial velocity (e.g. CARMENES, NIRPS+HARPS), this work is of fundamental importance for stellar and therefore planetary parameter determination.

The 10 parsec sample in the Gaia era

“…More than half of the M dwarfs (57.0 ± 7.3%) have spectral types M3.0 V to M5.0 V. This proportion remains stable when including the estimated spectral types of the unresolved secondary components (57.4 ± 6.9%). Translating these numbers into an observed mass function requires some care, but it seems to indicate that the number of stars increases up to about 0.3 M (∼ M4.0 V; Cifuentes et al 2020) and decreases for later M spectral subtypes. This maximum of the mass function, similar to other slope changes observed in very young open clusters (e.g.…”

CARMENES input catalog of M dwarfs

“…2.1, we extracted flux predictions in four filter bands (Johnson B and V and Gaia G BP , G RP ) from the theoretical spectra. Since the magnitudes in these bands have been measured for the majority of the CARMENES GTO sample (Cifuentes et al 2020), we were then able to compare the measured colors G BP − G RP and B − V to the theoretical predictions, as displayed in Fig. 7.…”

Two Planets Straddling the Habitable Zone of the Nearby K Dwarf Gl 414A

“…Our final adopted stellar parameters and associated uncertainties are listed in Table 1. Cifuentes et al (2020) derived stellar parameters for Gl 414A and found that T eff =4100 K, R å =0.7016±0.0177 R e , L å =1.2530±0.0016 L e , and M å =0.7136±0.0234 M e . All of these values are in agreement with ours, to within 1σ.…”