HELAS is a Coordination Action funded under the European Commission's Sixth Framework Programme (FP6) since April 1st, 2006 till March 31st, 2010. The HELAS Consortium includes 10 partner institutions that host researchers active in helio- and asteroseismology. This initiative offers a unique chance to advance the field further by coordinating the

Convective instability has been a mechanism used to explain the formation of solar photospheric flux tubes with kG field strength. However, the turbulence of the Earth's atmosphere has prevented ground-based observers from examining the hypothesis with precise polarimetric measurement on the subarcsecond scale flux tubes. Here we discuss

Context: Astrometric observations of resolved binaries provide estimates of orbital periods and will eventually lead to measurement of dynamical masses. Only a few very low mass star and brown dwarf masses have been measured to date, and the mass-luminosity relation still needs to be calibrated. Aims: We have monitored 14 very low mass multiple

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In our original paper (Section 4.4) we compared the ratios of hard X-ray to nuclear mid-infrared emission for Seyfert 1 and 2 (Sy1 and Sy2) nuclei, finding that both distributions appear significatively different according to the Kolmogorov-Smirnov test. We have detected a mistake in the computation of the X-ray luminosities (the lack of a 4π

Aims:We investigate the spatial distribution of magnetic polarities in the penumbra of a spot observed very close to disk center. Methods: High angular and temporal resolution magnetograms taken with the Narrowband Filter Imager aboard Hinode are used in this study. They provide continuous and stable measurements in the photospheric Fe I 630.25