Proposals are invited for observations with the APEX telescope and the Onsala Space Observatory 20 m telescope in the observing period starting mid-August 2012 (APEX) and 1 September 2012 (OSO 20m).

Deadline: 15 April 2012.

APEX is a 12 m diameter submillimetre telescope in Chile. The available facility receivers are the Swedish Heterodyne Facility Instrument covering a wide frequency range (211-370 GHz), the LABOCA bolometer array camera (345 GHz), and the SABOCA bolometer array camera (850 GHz). (There are also PI instruments.) Swedish time on APEX is open for scientists from all countries. Note: The APEX-3 and APEX-T2 receivers are not available. There will possibly be a separate Call for proposals for APEX-3 when it has been released for general use.

The Onsala 20 m diameter telescope in Sweden is equipped with heterodyne receivers for 18-50 GHz and 85-116 GHz. The telescope is open for scientists from all countries.

More details can be found in the links in the left column.

Calls for proposals for single-dish observations with the Onsala 20 m telescope and APEX are normally issued twice per year, with deadlines 15 April and 15 October. VLBI-observations are handled through a separate proposal procedure (not by Onsala Space Observatory).

Calls for proposals for observations with some other related instruments can be found here:

• The European VLBI Network (EVN)
• ALMA Science Portal at ESO
• European Southern Observatory (ESO) - Science Users Information