Communiqués de presse

Subscribe to receive news from ESO in your language!
eso9940 — Communiqué de presse institutionnel
The VLT Writes Its Name
13 août 1999: A computer-controlled "Active Optics" system was first developed at ESO in the 1980's. It allows the continuous tuning of the optical system of an astronomical telescope, thus ensuring that it always produces the sharpest possible images of astronomical objects. The first major telescope to profit from this revolution in telescope techniques was the ESO New Technology Telescope (NTT) at the La Silla observatory. Since it began operation in 1990, 75 adjustable supports below the 3.58-m primary mirror, coupled with advanced image analysis and control software, have made this prototype telescope one of the best in the world. Each of the four ESO Very Large Telescope (VLT) Unit Telescopes is equipped with the latest, improved active optics system that controls the primary 8.2-m Zerodur mirror as well as the secondary 1.1-m lightweight beryllium mirror at the top of the telescope structure. This system offers complete control of the optical quality, allowing the VLT to take full advantage of the exceptional atmospheric conditions at Paranal. This is amply confirmed by fine quality of the astronomical observations now performed with the first Unit Telescope, ANTU. In the course of the one-year commissioning period (May 1998 - March 1999), ESO's opticians performed extensive tests and further improvements of the active optics system at ANTU. Here are some interesting examples that illustrate the amazing versatility of this front-line technological system.
Lire plus
eso9915 — Communiqué de presse scientifique
VLT Studies Very Distant Galaxies
27 février 1999: Continuing progress in astronomical technology is opening new possibilities for the study of the distant universe. One of the most exciting, recent additions to this branch of astrophysics, known as cosmology, has been the discovery of a large population of galaxies in the primordial Universe in which intensive star-formation is going on. They are so distant (their redshifts are larger than 3 [1]) that the corresponding look-back time is over 90% of the age of the Universe, now estimated at about 14 - 15 billion years (1 billion = 1,000 million). We observe these objects as they were, when the Universe was between 1 and 2 billion years old. The investigation of the early Universe is one of the primary scientific goals that have motivated the construction of the ESO Very Large Telescope and its very diverse complement of instrumentation. The aim of these studies is to extend the observations of basic properties of galaxies to objects at the largest possible distances and hence the earliest possible epochs. We would like to learn as much as possible about these very faint galaxies, including their numbers and hence their space density, as well as their brightness, colours, sizes and shapes. What are the rates with which stars are formed in different galaxies at different epochs, what is their chemical composition and mass? How do they move in space and how do they cluster?
Lire plus
Affiche de 901 à 1000 de 1278