Mg II h+k Flux - Rotational Period Correlation for G-type stars
arXiv:1310.3890 · doi:10.1086/674332
Abstract
We present an analysis of the correlation between the mid-UV Mg II h and k emission lines and measured rotational periods of G-type stars. Based on IUE and HST high resolution spectra of a sample of 36 stars, we derive an exponential function that best represents the correlation. We found that the variation of the Mg II h + k fluxes is about a factor of 2.5 larger than that of Ca II H+K, indicating that the UV features are more sensitive to the decline of rotational period. The comparison of UV-predicted rotational periods with those derived from empirical Prot - Ca II H+K flux calibrations are consistent, with some scatter at large periods, where the emission are less intense. We present newly derived rotational periods for 15 G-type stars.
9 pages, 5 figures, 4 tables. Accepted for publication in PASP (corrected references)
References in corpus (5)
- Stellar Diameters and Temperatures III. Main Sequence A, F, G, & K Stars: Additional high-precision measurements and empirical relations
- Metallicities & Activities of Southern Stars
- Mg II h + k emission lines as stellar activity indicators of main sequence F-K stars
- Synthetic Mid-UV Spectroscopic Indices of Stars
- Tracers of chromospheric structure. I. CaII HK emission distribution of 13000 F, G and K stars in SDSS DR7 spectroscopic sample