La Silla Observatory is an astronomical observatory in
Chile with three telescopes built and operated by the European Southern Observatory (ESO). Several telescopes are located at the site and are partly maintained by ESO. The observatory is one of the largest in the Southern Hemisphere and was the first in Chile to be used by ESO.
The La Silla telescopes and instruments are located at the outskirts of the Chilean
Atacama Desert, one of the driest and loneliest areas of the
World. Like other observatories in this geographical area, La Silla is located far from sources of light pollution and, like the
Paranal Observatory, home to the Very Large Telescope, it has one of the darkest night skies on the Earth.
Telescopes
ESO operates three major optical and near infrared telescopes at the La Silla site:the New Technology Telescope (NTT), the 3.6-m ESO Telescope, and the 2.2-m Max-Planck-ESO Telescope.In addition La Silla hosts several other national and project telescopes: the 1.54-m Danish Telescope, the 1.2-m Leonhard Euler Telescope, the Rapid Eye Mount Telescope and the TAROT Telescope. These telescopes are not operated by ESO and hence do not fall under the responsibility of La Silla Science Operations.
New Technology Telescope
The ESO New Technology Telescope (NTT) is an Alt-Az, 3.58m Richey-Chretien telescope which pioneered the use of active optics. The telescope and its enclosure had a revolutionary design for optimal image quality.NTT saw first light in March 1989.The telescope chamber is ventilated by a system of flaps which optimize the air flow across the NTT minimizing the dome and mirror seeing. To prevent heat input to the building, all motors in the telescope are water cooled and all the electronics boxes are insulated and cooled.
The primary mirror of the NTT is actively controlled to preserve its figure at all telescope positions. The secondary mirror position is also actively controlled in three directions. The optimized airflow, the thermal controls, and the active optics give the excellent image quality of the NTT. Note that the NTT has active instead of adaptive optics: it corrects the defects and deformation of the telescope and mirror, but does not correct the turbulence; it ensures that the optics is always in perfect shape. Together with the thermal control, it allows the NTT to reach the ambient seeing, but it does not improve it.
3.6 m ESO Telescope
This 3.6 m Cassegrain telescope started operations in 1976 and has been constantly upgraded since, including the installation of a new secondary mirror that has kept the telescope in its place as one of the most efficient and productive engines of astronomical research.The telescope hosts HARPS, the High Accuracy Radial velocity Planet Searcher, the world’s foremost exoplanet hunter. HARPS is a spectrograph with unrivalled precision and is the most successful finder of low-mass exoplanets to date.Since April 2008, HARPS is the only instrument available at the 3.6 m telescope.
2.2 m MPG/ESO Telescope
The 2.2-metre Telescope has been in operation at La Silla since early 1984 and is on indefinite loan to ESO from the Max Planck Society (Max Planck Gesellschaft or MPG in German). Telescope time is shared between MPG and ESO observing programmes, while the operation and maintenance of the telescope are ESO’s responsibility.The telescope hosts three instruments: the 67-million pixel Wide Field Imager with a field of view as large as the full Moon, which has taken many amazing images of celestial objects; GROND, the Gamma-Ray Burst Optical/Near-Infrared Detector, which chases the afterglows of the most powerful explosions in the Universe, known as gamma-ray bursts; and the high-resolution spectrograph, FEROS, used to make detailed studies of stars.
Scientific Discoveries
With about 300 refereed publications attributable to the work of the observatory per year, La Silla remains at the forefront of astronomy. La Silla has led to an enormous number of scientific discoveries, including several "firsts". The HARPS spectrograph is the undisputed champion at finding low-mass extrasolar planets. It detected the system around Gliese 581, which contains what may be the first known rocky planet in a habitable zone, outside the Solar System.Several telescopes at La Silla played a crucial role in linking gamma-ray bursts.
the most energetic explosions in the Universe since the Big Bang — with the explosions of massive stars. Since 1987, the ESO La Silla Observatory has also played an important role in the study and follow-up of the nearest recent supernova, SN 1987A.On February 2, 2011, astronomers using the Wide Field Imager on the 2.2m telescope discovered an unusual pure disk galaxy christened NGC 3621.
