The Polaris proposal tool is where you can compose and store your Regular and ToO observing proposals, including defining targets and text for both scientific and technical justification.
Proposing an Observation with Polaris
An observer's guide to the use of Polaris can be found by clicking here. A brief description of the Polaris notes for the e-MERLIN Cycle 21 call for proposals and example proposal LaTeX files can be found on this page. If you haven't used the Polaris Proposal Tool before, you will need to set up a new login and password. To access the Polaris tool, simply click the icon below.
Polaris Webinar on 12th November at 1300 GMT
To aid in the submission of e-MERLIN proposals for Cycle 21, members of the e-MERLIN support team will be running a webinar to go through the basics of the Polaris tool and answer any questions. Information for this webinar can be obtained by contacting the e-MERLIN support team via email..
Frequently Asked Questions on the Cycle 21 e-MERLIN Call for proposals and use of Polaris
The new Polaris tool differs in several ways to NorthStar, and as a consequence some changes have been made to the way we accept proposals for e-MERLIN for Cycle 21. Only proposals submitted through the Polaris tool will be considered for Cycle 21. If you require proposals submitted in previous e-MERLIN semesters, please get in contact with the e-MERLIN support team via email. stating the proposal code and PI name in the body of the email. If you have any issues with the Polaris tool, please get in contact with e-MERLIN Support. We would also be grateful for feedback on the tool, as well as any accompanying documentation and will be in touch with users after the proposal deadline for their thoughts.
Proposal format, Page limits, font and margins
The format of e-MERLIN proposals has not changed: a science justification and technical justification are still required in order to submit a proposal. The Polaris tool has separate places for these to be uploaded. Unlike previous semesters, there are no explicit page limits for the e-MERLIN Cycle 21 Call for Proposals. However, the science justification is limited to 15000 characters (including spaces) and the technical justification is limited to 5000 characters (including spaces). The character limit includes all LaTeX commands and labels. The Polaris tool will not allow you to exceed these limits. As the Polaris tool uses LaTeX with a set backend for formatting the LaTeX files, you will not be able to change margins or font sizes. To aid with proposal creation, template proposal files can be found in this tar file.. The tar file includes the standard Polaris formatting files that will allow you to write your proposal away from the Polaris tool, and then simply copy the files LaTeX files across before submission. The character limits, margins and font sizes have been specified to ensure similarity in length between previous e-MERLIN proposals and Cycle 21. As such, we expect that Cycle 21 proposals should be approximately 4 pages long, including images. Please note that in future cycles these limits may change.
Dual Anonymisation
Since Cycle 18, e-MERLIN proposals have been subject to Dual-Anonymous Guidelines. These guidelines will also be used in Cycle 21. Please note that the e-MERLIN Time Allocation Group reserve the right to reject any proposal found to be in major violation of these guidelines. Information that should not be anonymised, such as relevant related proposals and student status of investigators should be included as part of an Additional Information File. This file is freeform but a template LaTeX Additional Information File can be found here. This file, once completed, must also be uploaded to the Polaris tool.
References
Your proposals should include references, but these are specified through a separate refs.bib file which is uploaded to Polaris. Consequently, the bibliography is not included in the character limits, but the citations in the LaTeX files are included in the character limits of the science and technical justifications.
When including citations in captions in Polaris, if you get errors during the compilation stage then it is sometimes useful to type "\protect" before the citation.
Addition of co-authors to proposals
To add co-authors to your Polaris proposal for Cycle 21, they must also be signed up to Polaris. Please ensure that your co-authors are aware of this and create an account in good time before the proposal deadline.
What are the expected time frames of the submission and Cycle 21?
Proposals will be sifted after the deadline on 20th November 2025. PIs can expect to have a response from the e-MERLIN TAG about the status of their proposal between late December and early January. Successful PIs will be contacted by the e-MERLIN support team to start planning of their observation in late January. The Cycle starts on February 1st 2026.







