The relation between Ca bright grains and oscillations in the photosphere
Kwasan and Hida Observatories, Kyoto University, Kyoto 607-8471 Japan e-mail: email@example.com
Accepted: 25 November 2005
Context.Ca bright grains are small and repetitive brightenings ubiquitously found in the quiet Sun.Aims.The relationship between the formation of Ca bright grains and the dynamics in the chromosphere and the photosphere is studied.Methods.We simultaneously observed the time series of spectra in Ca II H, Hα, and Fe I with the horizontal spectrograph of the Domeless Solar Telescope (DST) at Hida Observatory.Results.Our wavelet analysis revealed that the occurrence of Ca II H brightenings are correlated with enhanced 5 mHz velocity oscillations in the chromosphere and the photosphere.Conclusions.Ca bright grains can be explained by acoustic shocks in the chromosphere that are associated with 5 mHz oscillations in the photosphere below.
© ESO, 2006