Telescopes

Laboratory verification of Fast & Furious phase diversity: Towards controlling the low wind effect in the SPHERE instrument

Context. The low wind effect (LWE) refers to a characteristic set of quasi-static wavefront aberrations seen consistently by the SPHERE instrument when dome-level wind speeds drop below 3 ms$^-1$. The LWE produces bright low-order speckles in the …

Instrumental polarisation at the Nasmyth focus of the E-ELT

The åisebox-0.5ex~39-m European Extremely Large Telescope (E-ELT) will be the largest telescope ever built. This makes it particularly suitable for sensitive polarimetric observations, as polarimetry is a photon-starved technique. However, the …

Design and development of the Advanced Technology Solar Telescope

Led by the National Solar Observatory, plans have been made to design and to develop the Advanced Technology Solar Telescope (ATST). The ATST will be a 4-m general-purpose solar telescope equipped with adaptive optics and versatile post-focus …

The Advanced Technology Solar Telescope

The Advanced Technology Solar Telescope is the largest solar optical facility currently under development. The National Solar Observatory and its partners have just started the design and development phase with first light being planned for late this …

Solar speckle polarimetry

The combination of a polarimeter with real-time frame selection and differential speckle imaging results in diffraction-limited magnetograms that provide new insight into the morphology of solar small-scale magnetic fields. The method to record …