These are the most detailed pictures ever taken of the surface of the Sun. They have been described as a breakthrough in observational solar physics.

They were obtained by the new Swedish 1-metre solar telescope on the Canary Island of La Palma. The images show new solar features and hitherto unknown details in sunspots.

A striking feature in the images of sunspots is the existence of dark cores within bright filaments. This is an unexpected discovery and astronomers are uncertain what it signifies.
Link to photos here.