2015/09/15 by I. C. Leão, L. Pasquini, C. E. Ferreira Lopes +9 · 1 citation
Earth and Planetary Sciences · Physics and Astronomy · #Distribution (mathematics) #Geophysics and Gravity Measurements #Kepler #Light curve #Rotation (mathematics) #Rotation period #Solar and Space Plasma Dynamics #Stars #Starspot #Stellar rotation #Stellar, planetary, and galactic studies #astro-ph.SR
paper · pdf · doi:10.1051/0004-6361/201526085
published as A&A 582, A85 (2015) · 13 pages, 8 figures, A&A accepted
arxiv created 2015/09/15 · openalex publication_date 2015/09/17 · arxiv updated 2015/10/14 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
<i>Aims. <i/>We study the distribution of the photometric rotation period (<i>P<i/><sub>rot<sub/>), which is a direct measurement of the surface rotation at active latitudes, for three subsamples of Sun-like stars: one from CoRoT data and two from <i>Kepler <i/>data. For this purpose, we identify the main populations of these samples and interpret their main biases specifically for a comparison with the solar <i>P<i/><sub>rot<sub/>.<i>Methods. <i/><i>P<i/><sub>rot<sub/> and variability amplitude (<i>A<i/>) measurements were obtained from public CoRoT and <i>Kepler <i/>catalogs, which were combined with public data of physical parameters. Because these samples are subject to selection effects, we computed synthetic samples with simulated biases to compare with observations, particularly around the location of the Sun in the Hertzsprung-Russel (HR) diagram. Publicly available theoretical grids and empirical relations were used to combine physical parameters with <i>P<i/><sub>rot<sub/> and <i>A<i/>. Biases were simulated by performing cutoffs on the physical and rotational parameters in the same way as in each observed sample. A crucial cutoff is related with the detectability of the rotational modulation, which strongly depends on <i>A<i/>.<i>Results. <i/>The synthetic samples explain the observed <i>P<i/><sub>rot<sub/> distributions of Sun-like stars as having two main populations: one of young objects (group I, with ages younger than ~1 Gyr) and another of main-sequence and evolved stars (group II, with ages older than ~1 Gyr). The proportions of groups I and II in relation to the total number of stars range within 64–84% and 16–36%, respectively. Hence, young objects abound in the distributions, producing the effect of observing a high number of short periods around the location of the Sun in the HR diagram. Differences in the <i>P<i/><sub>rot<sub/> distributions between the CoRoT and <i>Kepler <i/>Sun-like samples may be associated with different Galactic populations. Overall, the synthetic distribution around the solar period agrees with observations, which suggests that the solar rotation is normal with respect to Sun-like stars within the accuracy of current data.