We describe and apply the methods that have been developed to calibrate the Advanced Stokes Polarimeter and to compensate for the polarization effects...

Aims: We introduce the Chromospheric Telescope (ChroTel) at the Observatorio del Teide in Izaña on Tenerife as a new multi-wavelength imaging telescope for full...

New narrow band images of NGC 4151, taken in excellent seeing conditions with the 4.2-m William Herschel Telescope on La Palma are presented. These reveal a...

New narrow-band images of NGC 4151, taken in excellent seeing conditions with the 4.2-m William Herschel Telescope are presented. These reveal a wealth of...

The importance of forbidden line radiation is considered, taking into account lines in the visible and the infrared range. The result of a theoretical study...

The errors associated with a segmented primary mirror limit the image quality obtainable with those astronomical telescopes which employ them. It is necessary...

The European Solar Telescope (EST) is a project to design, build and operate an European Solar 4-meter class telescope to be located in the Canary Islands, with...

The European Solar Telescope (EST) is a project aimed at studying the magnetic connectivity of the solar atmosphere, from the deep photosphere to the upper...

Gaia is a cornerstone mission in the science programme of the EuropeanSpace Agency (ESA). The spacecraft construction was approved in 2006, following a study in...