Onsala Space Observatory
Onsala Space Observatory (OSO), the Swedish National Facility for Radio Astronomy, provides scientists with equipment to study the Earth and the rest of the Universe. The observatory operates two radio telescopes in Onsala, 45 km south of Gothenburg, and takes part in several international projects. Examples of activities: Onsala Space Observatory was founded in 1949 by professor Olof Rydbeck. The observatory is hosted by Department of Earth and Space Science at Chalmers University of Technology, and is operated on behalf of the Swedish Research Council. 25-metre telescope. The 25.6 m diameter, polar mount decimeter-wave telescope  in Onsala is equipped with receivers for frequencies up to 7 GHz. It is used for astronomical VLBI observations. It is also operated as a single dish for studies of molecular clouds in the Galaxy. The telescope was built in 1963. 20-metre telescope. The 20 m diameter millimetre wave telescope in Onsala is equipped with receivers for frequencies up to 116 GHz. It is used for observations of millimetre wave emission from molecules in comets, circumstellar envelopes, and the interstellar medium in the Galaxy and in extragalactic objects. The telescope is enclosed in a radome of diameter 30 m.  It is also used for astronomical VLBI observations of star forming regions, radio stars, and active galactic nuclei, and for geodetic VLBI observations to study e.g. crustal dynamics and polar motion. The telescope was built in 1975-76 and upgraded in 1992. It is also used, as part of the European and worldwide networks, for astronomical Very Long Baseline Interferometry (VLBI) observations of star forming regions, radio stars, and active galactic nuclei, and for geodetic VLBI observations to study e.g. crustal dynamics and polar motion. Receivers. The telescope is equipped with the following receivers: LOFAR station. The Swedish station in  the international radio telescope LOFAR is located at Onsala Space Observatory. It was completed in 2011. Nordic ALMA node. The Onsala Space Observatory currently hosts the Nordic ALMA node, which is part of the European ALMA regional centre (ARC). The Nordic ALMA node provides face-to-face support for any astronomer that wants to use the ALMA telescope and primarily supports the Nordic scientific community.