VLT Survey Telescope


The VLT Survey Telescope (VST) is the latest telescope to be installed at ESO’s Paranal Observatory (eso1119). It is the largest telescope in the world designed for surveying the sky in visible light. This state-of-the-art 2.6-m telescope will be joining the ESO VLT on Cerro Paranal, a perfect location for ground-based astronomical observations. It will be equipped with an enormous 268-megapixel camera called OmegaCAM that will be the successor of the very successful Wide Field Imager (WFI) currently installed at the 2.2-m MPG/ESO Telescope on La Silla.

Like the VLT, the new survey telescope will cover a wide-range of wavelengths from ultraviolet through optical to the near-infrared (0.3 to 1.0 microns). But whereas the largest telescopes, such as the VLT, can only study a small part of the sky at any one time, the VST is designed to photograph large areas quickly and deeply.

With a total field view of 1°x 1°, twice as broad as the full Moon, the VST was conceived to support the VLT with wide-angle imaging by detecting and pre-characterising sources, which the VLT Unit Telescopes can then observe further.

The VST will be comprised of two mirrors, a primary mirror (M1) with a diameter of 265 cm and a smaller secondary mirror (M2) with a 93.8 cm diameter. The telescope will also be equipped with a single dedicated focal plane instrument: OmegaCAM. This huge (16k x 16k pixels) CCD camera was built by an international consortium of five institutions: Netherlands Research School for Astronomy (NOVA), Kapteyn Astronomical Institute, Universitäts-Sternwarte München, Astronomical Observatory of Padova and ESO.

Science with the VST

The VST will be dedicated to survey programmes. With its state-of-the-art camera, the quality of its optics, and the exceptional seeing conditions of Paranal, VST has the potential to make important discoveries in a wide of areas of astrophysics and cosmology. In planetary science, the survey telescope aims to discover and study remote Solar System bodies such as trans-Neptunian objects, as well as search for extrasolar planet transits. The Galactic plane will also be extensively studied and will provide astronomers with data crucial to understand the structure and evolution of our Galaxy. Further afield, the VST will explore nearby galaxies, extragalactic and intra-cluster planetary nebulae, and will perform surveys of faint object and micro-lensing events. In the field of cosmology, the VST will target medium-redshift supernovae to help pin down the cosmic distance scale and understand the expansion of the Universe. The VST will also look for cosmic structures at medium-high redshift, active galactic nuclei and quasars to further our understanding of galaxy formation and the Universe’s early history.

The VST project is a joint venture between the European Southern Observatory and the Capodimonte Astronomical Observatory (OAC), part of the Italian National Institute for Astrophysics (INAF). The Italian centre designed the telescope while ESO is responsible for the civil engineering works at the site.

The telescope became operational in 2011.

Science goals

Devoted to surveys. Remote solar system bodies (TNO, KBO), Milky way, extragalactic planetary nebulae, cosmology.

More about the VST


Name: VLT Survey Telescope
Site: Cerro Paranal
Altitude: 2635 m
Enclosure: Compact optimised cylindrical enclosure
Type: Optical survey telescope
Optical design: Modified Ritchey-Chrétien Reflector with correctors
Diameter. Primary M1: 2.61 m
Material. Primary M1: Astro-Sitall
Diameter. Secondary M2: 0.938 m
Material. Secondary M2: Astro-Sitall
Mount: Alt-Azimuth fork mount
First Light date: 8 June 2011
Active Optics: Yes