Nearly all 4MOST components have now arrived at the Paranal Observatory. Meanwhile, the VISTA telescope has been successfully recommissioned following the modifications required to accommodate 4MOST. The reintegration of the various components—such as the spectrographs and fiber positioner—has now begun, with installation on the telescope scheduled over the coming months. Commissioning will continue through the end of the year, with the five-year survey expected to begin in the first half of 2026.
4MOST Arrives in Paranal
Published: 02 Jul 2025
4MOST will offer the ESO community a world-class optical spectroscopic survey facility. Its unique capabilities are made possible by a combination of a large field of view, high multiplexing, broad optical spectral coverage, and a dedicated telescope located at a premier astronomical site: VISTA at Paranal. As a spectroscopic survey facility, 4MOST will operate differently from standard observatory operations. To maximize fiber usage and accommodate surveys with low target densities, all 4MOST surveys will be merged into a single, simultaneous observing program which will last 5 years. 4MOST surveys are ESO public surveys with regular data releases (see the associated timeline here).
The 4MOST Consortium is led by Roelof de Jong (Principal Investigator) and Joar Brynnel (Project Manager) from AIP, with support from a broad partnership of institutes in Europe, United Kingdom, and Australia.