Sökresultat

Euro 50 - A 50 m Adaptive Optics Extremely Large Telescope

Observing RV Tauri and SRd variables with GAIA

Chemical Evolution of the Galactic Disk(s)

We highlight some results from our high-resolution spectroscopic elemental abundance survey of F and G dwarf stars in the solar neighbourhood.

Tilt anisoplanatism and PSF retrieval in LGS MCAO using a predictive controller

It is shown how tilt anisoplanatism in laser-supported multi-conjugatedadaptive optics (MCAO) systems can be a) predicted from a prioriknowledge, b) compensated using additional natural guide stars (NGS),and c) estimated in real time from control loop data to allow PSFretrieval. As a consequence of the problems associated with retrievingatmospheric tip and tilt from laser guide star (LGS) measurem

Chemical abundances in cool metal rich disk dwarf stars

The present study of spectra of twelve metal-rich cool dwarf stars, carefully selected in order to cover a range of temperatures ( K), is a follow up on Feltzing & Gustafsson (1998) with the aim to understand the apparent over-ionization and anomalous elemental abundances found by them for the K dwarf stars in their sample. Our method of analysis employs synthetic spectra of the full spectrum

3D Hydrodynamical Modelling of the Solar Chromosphere

We report on 3D radiation-hydrodynamics modelling of the non-magneticsolar atmosphere with emphasis on the problem of the acoustic heating ofthe chromosphere. Our models include the generation of acoustic waves inthe uppermost layers of the solar convection zone their propagationthrough the photospheric layers and their ultimate transformation intoshock fronts which are dissipated in the chromosph

Euro50: Proposal for a 50 m Optical and Infrared Telescope

Staff from Instituto de Astrofisica de Canarias, Lund Observatory,Physics Department and Larmor Research Institute at Galway, and TuorlaObservatory is collaborating on studies for a 50 m optical and infraredtelescope. The telescope concepts are based on the work on extremelylarge telescopes carried out during 1991-2000 at Lund Observatory, andon the experience from the 10.4 m segmented Grantecan t

Very fast photon counting photometers for astronomical applications: from QuantEYE to AquEYE

The Gaia mission: Science, organization and present status

QuantEYE. Quantum Optics Instrumentation for Astronomy

QuantEYE: The Quantum Optics Instrument for OWL

Concepts for Dual Conjugate Adaptive Optics for the Swedish 50 m Extremely Large Telescope

The Hipparcos Catalogue

Absolute Lineshifts - a new diagnostic for stellar hydrodynamics

Evolution of Galaxies from ELT Photometry of Stellar Clusters

Effective outer scale estimation for Euro50 site

Dual-conjugate AO performance for ELTs. Mirror Dynamical Range and Acuator Pitch

New phenomena discovered in the atmospheres of normal late-B type stars

We report detections of weak emission lines in main sequence B starspectra observed at high spectral resolution and high signal-to-noiseratio. The emission lines originate from highly excited states ofsingle-ionized species. The mechanism for populating these excitedstates is currently under investigation and the results may have asignificant bearing upon our understanding of the outermost atmosph

Magnetic Field Diagnosis in HgMn Stars

The Age of the Metal-Rich Globular Cluster NGC 6352