A set of series of spectra of high spectral resolution corresponding to the same umbra on several days, is used to study the oscillations related to evolution...

Context. The thermal structure of the penumbra below its visible surface (i.e., τ5 ≥ 1) has important implications for our present understanding of sunspots and...

Context. Far-side helioseismology is a technique used to infer the presence of active regions in the far hemisphere of the Sun based on the interpretation of...

We investigate the dynamics of and the relations between small-scale penumbral and photospheric features near the outer penumbral boundary: penumbral grains...

Two time series, taken simultaneously in the G-band and in white-light, and corrected for telescope aberrations and turbulence perturbations using the method of...

The decay of a sunspot region was studied using high resolution white-light pictures. The photometric and geometric parameters of a light-bridge showing...

The authors present the results of a statistical analysis of the penumbra of sunspots. The intensity distribution, and several parameters derived from it, is...

White-light images, centered at λ6708A, were obtained at the Swedish Solar Telescope, La Palma, on occasion of the 1994 May 10 partial solar eclipse. From the...

We present new high-resolution spectro-polarimetric Ca IIλ8542 observations of umbral flashes in sunspots. At nearly 0.18 arcsec, and spanning about one hour of...