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Regular proposals

Regular proposals cover several different types of observations, all of which are explained below.

For all regular proposals:

  • Proposals are submitted via the NorthStar proposal tool.

  • Both disk and e-VLBI observations can be requested in the same proposal.

  • Abstracts of successful proposals are published in the EVN Data Archive.


Information on the submission of Target of Opportunity and short requests can be found elsewhere.

Investigators named on an EVN or global VLBI proposal have the sole right of access to the data obtained for that proposal for 12 months after the distribution of the data to the Principal Investigator. If the proposal comprises multiple observations then the 12 month period begins from the distribution of the final observation associated with the proposal.

For Target-of-Opportunity proposals, this proprietary period is 6 months, owing to the time-critical nature of such experiments.

One month prior to the public release of data from a proposal, JIVE will inform the Principal Investigator (at the last known e-mail address) about the impending action. Under exceptional circumstances the Principal Investigator can request a short delay in the release date. All such requests should be made to the Chair of the EVN Programme Committee.

Following the expiry of the proprietary period for a proposal, all data related to it will be publicly accessible.


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General information about the proposal submission

Proposals are submitted as a single PDF document, consisting of four pages (A4 or US letter format, font size ≥ 11 pt)

A proposal must include:

  • Scientific justification,

  • Technical justification (see EVN capabilities) - all ESSENTIAL antennas must be identified,

  • References (if citations are used).

  • A brief summary of related EVN proposals.

Supporting figures and tables are encouraged.

If the proposal is a resubmission, this must be indicated.

Disk and/or real-time EVN (e-VLBI) observations can be requested. The request for e-VLBI observations must be clearly justified in the proposal.


NorthStar submission information

First time users must register at NorthStar

Information/documents to provide in NorthStar:

  • Proposal document consisting of the Scientific and Technical justification,

  • List of investigators, including institute and contact information

  • Observing request, including:

    • if e-EVN observations are required,

    • Requested waveband,

    • Requested network of telescopes,

    • Preferred observing dates,

    • Multi-epoch observations,

    • Recording format,

    • Processor information,

    • Target sources (coordinates, total flux density, correlated flux density, SNR, field of view).

Any additional issues, including:

  • Information about all involved students,

  • Linked proposals,

  • Relevant previous allocations of observing time.


Proposal submission is the responsibility of the contact author:

  • Online help in the North Star tool is available.

  • Retraction, editing and resubmission of proposals until the deadline is possible

  • An email will be sent to all co-investigators following submission.


If you require assistance throughout this process, contact JIVE.

Standard observations

Standard observations include disk and e-VLBI continuum and spectral line observations. The proposal preparation follows the guidelines described above.

Trigger observations

Continuum or spectral line observations requiring a single correlator pass can be requested as trigger proposals. In the proposal, it must be clearly justified why trigger observations are requested and why the target of opportunity mode is not suitable.

Trigger proposals must include: 

  • A list of potential targets* with an explanation of how these sources form a coherent set for achieving the goals of the proposal,

  • Well-defined trigger criteria, specified for each class of sources separately, if necessary,

  • Minimum number and configuration of telescopes required,

  • Desired period for which proposal is active (max duration 1 year - 9 months for automatic trigger proposals),

  • Maximum number of trigger events to be observed,

  • Demonstrate capability of proposers to locate and respond to triggering events within the active period of the proposal,

  • Required sensitivity,

  • Minimum/maximum observing time,

  • Justification as to why general e-VLBI observations or ToO is not suitable.

*In a generic trigger proposal, a list of targets does not have to be provided. 


Trigger observations can be done most naturally during e-VLBI runs because of the short response time (see below). Trigger activation in EVN Sessions is now also possible with the following restrictions:

  • performed on best effort basis; only if there is an available observing slot in the right frequency range and if media resources are sufficient
  • performed in disk-recording only
  • trigger activation should be done at least one week before the start of the desired frequency block in the schedule by writing a mail to the PC Chair

Note that not all gaps in the observing schedule may be available for observations!


Trigger requests, including accurate source coordinates, must be sent to the Chair of the EVN Programme Committee (with the EVN Scheduler and JIVE in copy) and received no later than 0800 UT the day before the e-VLBI run.

Trigger requests to be activated on an EVN-lite subarray day should be sent and received no later than 0800 UT 3 days before EVN-lite subarray run. Note that the EVN-lite subarray observations are done at 21cm. Stations may have limitations in changing frequency bands for EVN-lite triggers

Large observations proposals

Large observation proposals are intended for projects that request observing time of more than 48 hours.

These proposals are subject to more detailed scrutiny by the EVN Programme Committee.

Large observations can be proposed as global proposals.

For projects with several observing epochs, the EVN Programme Committee may request a progress report.

Out-of-session observations

The maximum observing time available for out-of-session projects is 144 hours/year. Out-of-session observing blocks are longer than 12 hours (individual observations can be shorter) and only up to 10 sessions can be scheduled each year (up to max. 144 hours).

Out-of-session proposals can be requested for disk and e-VLBI observations.

The scientific (and technical) justification should include an explanation as to why out-of-session observations are requested instead of in-session observations.

The proposal must include:

  • Observing dates,

  • GST ranges,

  • Minimum number of telescopes (and any specific telescopes if necessary).

Successful proposals will be scheduled following the regular EVN session, which occurs after the proposal review.


Inclusion of additional telescopes

Global proposals

In addition to the EVN antennas, global proposals can include some/all of the NRAO antennas (VLBA, VLA) and/or the GBO. Justification for their need and a plan for their use must be clearly outlined in the proposal.

The proposal, submitted via NorthStar, is automatically sent to the NRAO and is assessed separately by the EVN Programme Committee and the NRAO.

e-MERLIN and EVN affiliated stations


e-MERLIN stations can be included in any proposal requesting disk and/or e-VLBI observations but their inclusion must be clearly justified in the proposal. The proposal is judged and observing time allocated via the EVN Programme Committee and the e-MERLIN time allocation committee.


EVN affiliated stations

EVN affiliated stations are antennas of the NASA Deep Space Network (e.g. Robledo) and the Australian Long Baseline Array (LBA). Proposals can request to include these antennas in the EVN network, but their inclusion must be clearly justified in the proposal.

In the NorthStar submission tool, the LBA can be selected under 'Other' in the telescope-selection box.

Proposals including the LBA need to also submit a proposal to the LBA for their subsequent deadline.

Non-EVN stations

In the proposal, it needs to be specified which non-EVN stations will be included in the observations.

The investigators must send a copy of the proposal to the director/scheduler of the included observatory and arrange all aspects of the observatory's participation in the EVN observations (including acquiring telescope time from the observatory, observing support, disk supply, etc.)

More information on including non-EVN stations is given in the Code of Practice for Non-EVN observatories.