Rotation-Activity Correlations in K and M Dwarfs. I. Stellar Parameters and Compilations of v sin I and P/sin I for a Large Sample of Late-K and M Dwarfs
Abstract
The reliable determination of rotation-activity correlations (RACs) depends on precise measurements of the following stellar parameters: T eff, parallax, radius, metallicity, and rotational speed v sin I. In this paper, our goal is to focus on the determination of these parameters for a sample of K and M dwarfs. In a future paper (Paper II), we will combine our rotational data with activity data in order to construct RACs. Here, we report on a determination of effective temperatures based on the (R-I) C color from the calibrations of Mann et al. and Kenyon & Hartmann for four samples of late-K, dM2, dM3, and dM4 stars. We also determine stellar parameters (T eff, log(g), and [M/H]) using the principal component analysis-based inversion technique for a sample of 105 late-K dwarfs. We compile all effective temperatures from the literature for this sample. We determine empirical radius-[M/H] correlations in our stellar samples. This allows us to propose new effective temperatures, stellar radii, and metallicities for a large sample of 612 late-K and M dwarfs. Our mean radii agree well with those of Boyajian et al. We analyze HARPS and SOPHIE spectra of 105 late-K dwarfs, and we have detected v sin I in 92 stars. In combination with our previous v sin I measurements in M and K dwarfs, we now derive P/sin I measures for a sample of 418 K and M dwarfs. We investigate the distributions of P/sin I, and we show that they are different from one spectral subtype to another at a 99.9% confidence level.
Based on observations available at Observatoire de Haute Provence and the European Southern Observatory databases and on Hipparcos parallax measurements.- Publication:
-
The Astrophysical Journal
- Pub Date:
- May 2016
- DOI:
- 10.3847/0004-637X/822/2/97
- arXiv:
- arXiv:1604.07920
- Bibcode:
- 2016ApJ...822...97H
- Keywords:
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- stars: fundamental parameters;
- stars: late-type;
- stars: rotation;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 51 pages, 15 Figures, 7 Tables