Call for proposals

Observations with APEX, the Onsala 20 m telescope, and the Swedish LOFAR station 

(For EVN Call for Proposals, see the Astro VLBI page.)


Proposals are invited for observations with the APEX telescope, the Onsala Space Observatory 20 m telescope, and the Swedish LOFAR station in stand-alone mode, in the observing period August/September 2017 – March 2018.

Deadline: Friday 5 May 2017 (23:59:59 UTC)
Proposals for APEX and the Onsala 20 m telescope are to be submitted through the NorthStar system.


APEX, the Atacama Pathfinder EXperiment, is a 12 m diameter submillimetre telescope at 5100 m altitude on Llano Chajnantor in Chile.

The available facility receivers are the Swedish Heterodyne Facility Instrument (SHeFI) covering 211-500 GHz and the 870 μm LABOCA bolometer array.

The partner instrument ArTeMiS, a 350 and 450 μm bolometer array, will be available to all users on Swedish time.

SEPIA (Swedish ESO PI receiver for Apex) currently houses two heterodyne receivers: one for ALMA Band 5 (159–211 GHz, including the 183 GHz water line) and one for ALMA Band 9 (600–722 GHz). Proposals for observations with the SEPIA instrument must have a PI or co-I with a Swedish affiliation.

Other APEX partner instruments, including FLASH+, can also proposed for use during Swedish time, but use of the instrument must be discussed with the instrument PI before the submission of the proposal.

Note in particular the new receiver for 600–722 GHz (ALMA band 9).

Swedish time on APEX is open for scientists from all countries (but see above about SEPIA).

More information about APEX proposals.

Onsala 20 m

The Onsala 20 m diameter telescope in Sweden is equipped with receivers for 1850 GHz and 67116 GHz.

Note in particular the new receiver for 67–87 GHz and the new spectrometer with 2 x 4 GHz bandwidth.

The telescope is open for scientists from all countries.

More information about Onsala 20 m telescope proposals.


The Swedish LOFAR station at Onsala Space Observatory is an array of antennas for the frequency bands 10–90 MHz and 110–240 MHz. It is part of the International LOFAR Telescope (ILT), but is offered here in stand-alone mode. It is open for scientists from all countries.

More information about Swedish LOFAR station proposals.




Calls for proposals for single-dish observations with the Onsala 20 m telescope and APEX, and for stand-alone observations with the Swedish LOFAR station in Onsala, are normally issued twice per year, with deadlines in April/May and 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
> Low Frequency Array (LOFAR) 

Note: APEX data can be accessed through the ESO Science Archive APEX Query Form.

Published: Fri 30 Aug 2013. Modified: Wed 22 Mar 2017