The Hubble Space Telescope has facilitated major contributions to a wide range of topics in astronomy:

• The study of nearby planets
• The processes of star and planet formation
• The stellar and interstellar components of galaxies
• The discovery that most, if not all, galactic nuclei harbor a massive black hole that profoundly affects their evolution
• The realisation that the universe as a whole is undergoing acceleration as a result of a yet unknown form of "dark energy". This volume offers a broad perspective of the advancements made possible by the HST over its almost two decades of operation and emphasises their impact on European astronomical research. These proceedings of 41st symposium in the ESLAB series of the European Space Agency collect the oral and poster papers that were presented and discussed during the meeting.

Zusammenfassung
Remembrance of Things Past It scarcely seems credible that it was almost exactly thirty years ago that I ?rst met Duccio Macchetto at the ?rst meeting of the newly formed Science Working Group of what was then called the Space Telescope project. We were there in slightly d- ferent roles, Duccio as the project scientist for the Faint Object Camera and I as an interdisciplinary scientist. Henk van de Hulst was also there as the of?cial rep- sentative of ESO. The approval of the project was the end result of a great deal of lobbying and politicking both in the USA and Europe, the European contribution proving essential to the approval process in the USA. Those interested in the nit- gritty of the process should read Robert Smith's outstanding history of the Hubble Space Telescope. We should have realized early on that we were in for a rough time. At that ?rst meeting of the Science Working Group I remember vividly NASA Headquarters telling us that the Space Telescope was a success-oriented programme that would cost M$ 680. Well, we could live with the cost-tag, but we should have had concerns about the expression success-oriented. This meant that everything should turn out exactly as planned, the project would be carried out within the projected time-scale and budget and the telescope would be launched in 1983. Well, the rest is history. We learned a lot of useful jargon along the way.

Inhalt
Stars, star formation, stellar populations and planets.- Hot Massive Stars: The Impact of HST.- HST Spectroscopy of the Hottest White Dwarfs.- Key Abundance Tracers in the UV: From the Lightest to the Heaviest.- UV Spectroscopy of Metal-Poor Massive Stars in the Small Magellanic Cloud.- Star Formation Histories of Resolved Galaxies.- HST's View of the Youngest Massive Stars in the Magellanic Clouds.- Planetary Nebulae and Their Central Stars in the Magellanic Clouds.- A Look at Neutron Stars with HST: From Positions to Physics.- The HST Contribution to Neutron Star Astronomy.- Exotic Populations in Galactic Globular Clusters.- The Stellar Mass Function in Globular Clusters.- Early Phases of Protoplanetary Disk Evolution.- Unveiling the Role of Jets in Star Formation.- A View of Star Forming Regions in the Magellanic Clouds.- A Preliminary Budget for the Ionizing Photons in HII Regions of M51.- Nearby galaxies, bulges, spheroids and galaxy formation.- New HST Views at Old Stellar Systems.- Young Massive Star Clusters in the Era of the Hubble Space Telescope.- The Central Regions of Early-Type Galaxies.- Nuclear Star Clusters Across the Hubble Sequence.- Stellar Populations in the Outskirts of M31: The View from HST.- Variable Stars in Nearby Galaxies with HST.- Extremely Metal-Poor Star-Forming Dwarf Galaxies.- Resolved Stellar Populations in Nearby Galaxy Halos.- The Kinematics of Core and Cusp Galaxies: Comparing HST Imaging and Integral-Field Observations.- Resolving Extragalactic Star Clusters with HST/ACS.- Tracing Galaxy Evolution in Clusters and Groups at ?1.- The Dawn of Galaxies.- A Simple Physical Model for Young Galaxies in the Early Universe.- Diffuse Ionized Gas Halos Seen with HST.- Deep fields, AGN, black holes and radiogalaxies.- The Host Galaxy Properties of Powerful Radio Sources Across Cosmic Time.- A New View of the Origin of the Radio-Quiet/Radio-Loud AGN Dichotomy?.- The Bright and the Dark Side of Malin 1.- Cluster Lensing with Hubble.- HST Observations of Gravitationally Lensed QSOs.- Study of Quasar Host Galaxies Combining HST/ACS Images and VLT Spectra.- Local Lyman Emitters and Their Relevance to High Redshift Ones.- The HST View of Low Luminosity AGN.- The Black Hole Masses in Galactic Nuclei.- The HST/ACS Coma Cluster Treasury Survey.- Discovery of a Population of Evolved and Massive Galaxies at High Redshift.- Searching for High Redshift Galaxies Using Population Synthesis Models.- The ACS Grism Mode and ACS Grism Observations of Deep Fields and High Ly- Galaxies.- The Role of in the Study of Near- and Mid-infrared-selected Galaxies.- Large Scale Structure and Galaxy Evolution in COSMOS.- Mass Estimations of Supermassive Black Holes in Brightest Cluster Galaxies.- Near-UV Study of Active Galactic Nuclei with Advanced Camera for Surveys.- A Quantitative Analysis of the Morphology of Star Formation in a Sample of GOODS-HST/ACS Galaxies.- HST, H0 and dark energy.- Visiting Hubble in Orbit.- HST and JWST: Present and Future.- Enabling Science with the Hubble Legacy Archive.- Advanced Calibration Using Physical Instrument Models: HST, VLT and Beyond.- The Hubble Constant and HST.- Recent Progress on the Cepheid Distance Scale with.- Seeing Dark Energy.- Closing remarks.- Closing Remarks.