WSRT - astronomers

WSRT in the morning

The Westerbork Synthesis Radio Telescope is one of the most powerful radio observatories in the world. It enables astronomers to study a wide range of astrophysical problems: from pulsars to kinematics of nearby galaxies to the physics of black-holes.

The WSRT is an open user facility available for scientists from any country. It is also part of the European VLBI network (EVN) of radio telescopes. This allows the astronomers to obtain some of the sharpest and more detailed images possible in astronomy.

The forthcoming upgrade to the Apertif system, starting from the middle of  2015, is replacing the telescope's Multi-Frequency-Frontends (MFFEs) with Focal Plane Arrays (FPAs) and hence increasing the field of view by a factor of 30, will enable the WSRT to conduct fast surveys of the radio sky with the spatial resolution typical of a radio interferometer. With the experiences made in the operation of such systems and in the scientific exploit of large radio surveys, the WSRT will play a crucial role in the preparation of the Square Kilometer Array (SKA).



  • The MFFE receivers, and associated backends will termnate operations  on June 24, 2015.    The event is marked with a brief ceremony on that day, to mark the end of observations take place on that day, which incidentally is 45 years after the inauguration of the array by Queen Julliana.  During the summer of 2015, work the installation of the first 6 APERTIF systemsin the WSRT will intensify with the aim to achive first light in the autumn of 2015.
  • The final call for proposals with the MFFEs was  issued with a deadline on Monday 6 Oct 2014. The approved projects, for Semester 14B were observed until the middle of April 2015.
  • The latest deadline of regular proposals for the WSRT was at Friday 27 September (2013), 14:00 CEST (12:00 UTC). For more details please see the latest call for proposals.
  • Service Proposal admission: These can be submitted at any time, and can usually request up to 26 hours of telescope time. They are intended for quick verifications, pilots, acquisition of some ancillary data, etc., and, if approved, will receive "filler" priority for the running semester, without any guarantee of being carried out.
  • The dishes RT2, RT4, RT5 are used as a testbed for Apertif focal plane array developments, and are unavailable for regular astronomical observing since semester 12A. The overall sensitivity of the array will be correspondingly reduced to that of a 10-antenna array, but the uv-coverage will not be significantly impacted for most projects.

  • The WSRT LFFE receivers, covering 115 - 180 MHz, have been decommissioned and are not available anymore. LOFAR offers much more extensive capabilities in this band.

The NL PC proposal submission system Northstar

is accessible through a WEB-BASED INTERFACE.

First time users

should take note of this Instruction link
The web proposal tool is directly accessible through the Web Proposal Link

Unevenly distributed oversubscription

usually prevails; proposers significantly enhance their chances for success if they can tailor their programmes. Oversubscription rates at LST=12-18 are typically a factor of 3 to 5, due to the demand for long integrations on targets at high northern Galactic latitudes (RA=10 to RA=14) and in the inner Galaxy (RA=17 to RA=21). On the other hand, LST=00-06 may have an oversubscription of only 1 to 2, barring occasional large requests. In addition, projects which can be broken into small segments and do not need perfect HA coverage can be scheduled more flexibly, and are thus at an advantage, even if they need a large total integration time. Stringent demands for night-time 12-hr observing runs can only be met during limited periods, and are thus less likely to be scheduled.

Service Proposals

can be submitted at any time between deadlines, and can usually request up to 26 hours of telescope time. They are intended for quick verifications, pilots, acquisition of some ancillary data, etc., and, if approved, will receive "filler" priority for the running semester, without any guarantee of being carried out. 

Urgent Proposals

can submitted at any time between deadlines. They will be assessed on scientific excellence just like regular proposals, and must in addition demonstrate why the project could not be submitted before the last deadline and cannot wait for the next semester.

Support for European proposals

is available via the Trans-National Access programme of the RadioNet Consortium. The WSRT would like to encourage proposals from groups in which both the PI and at least 50% of the team members on the proposal are based in an EU or affiliated country other than The Netherlands (for specifics, see Such projects benefit both the WSRT and the eligible groups. They are entitled to reimbursement for a data analysis visit by one of their members to ASTRON; a staff member can be assigned for support at all stages from proposal writing to final data analysis. The WSRT hopes proposers are willing to take note of the EU encouragement to give their teams a European dimension; it brings valuable support!


Astronomers can send technical inquiries and requests for support by e-mail to wsrt-support [at] astron [dot] nl, where they will be answered or forwarded as needed.

Design: Kuenst.    Development: Dripl.    © 2015 ASTRON