CFHT Call for Proposals

The 2024B call for proposals for NRC, CNRS, ASIAA, and NAOC is open.

NRC and CNRS proposals deadline:
March 21, 2024 23:59 UT

ASIAA proposals deadline:
March 21, 2024 23:59 Taipei time

NAOC proposals deadline:
March 21, 2024 23:59 CST
GRACES is no longer offered at Gemini, and the CFHT/Gemini/GRACES exchange program has ended.

2024A DDT proposals - CFHT users interested in submitting a Director's Discretionary Time proposal for 24A are invited to read the Phase 1 Proposal Submission Instructions for information about the QSO Mode and our instruments, and the K1 tutorial for login information and help with the UI. DDT proposals must be submitted using Kealahou K1 after selecting the Discretionary agency. Kealahou now sends submission notifications. Saving a PDF for the record is recommended.

2024B proposals - CFHT users from the NRC (Canada), CNRS (France), ASIAA, or NAOC agencies and partners interested in submitting a proposal for semester 2024B are invited to first read this page for specific instructions regarding semester 2024B. The Phase 1 Proposal Submission Instructions provides important information about the QSO Mode, links to all instruments, their ETC, details of the overheads, and other important points specific to each instrument. The K1 tutorial includes login information for returning and new users, character limits and page limits for various sections, instructions on how to invite collaborators, and other details for each of the sections. Proposals must be submitted using Kealahou K1 after selecting the proper semester and agency. Kealahou now sends submission notifications. Saving a PDF for the record is recommended.

Prospective users applying for University of Hawai’i or the OPTICON-Radionet Pilot Trans-National Access programme OPTICON-Radionet Pilot Trans-National Access programme time should continue to use their respective agency's proposal submission tools.

Information on 2024B      [1 Aug 2024 - 31 Jan 2025]

News and specific notes for semester 2024B
Important technical notes
Additional instructions for Canadian proposals
Snapshot programs

News and specific notes for semester 2024B [Up]

WIRCam There was a filters change performed in 2023B on WIRCam. The filters available at the start of semester 2024B will be Y, J, H, Ks, H2, BrG, KCont, and LowOH1. The broad-band filters Y, J, H, Ks are always available. If you need a narrow-band filter currently not in WIRCam, you must provide a strong case why the requested narrow band filter is essential for your science goals, especially pointing out why you cannot use the filters currently available on the filter wheel.

Also note that even if you are awarded time, there is no guarantee your requested filter change will happen; you may be superseded by a higher ranked program also requesting another filter exchange.

New Halpha SITELLE filter CFHT offers a new filter (SN4) for SITELLE. It covers the spectral range 652-665 nm. The filter optical characteristics can be found here:

With respect to the broader SN3 filter around the same wavelengths, SN4 can be used (i) to increase the spectral resolution by a factor of two for the same number of steps, and/or (ii) to increase the S/N by a factor of 1.7 for a similar total on-source exposure (valid for emission-line objects).

The filter has not yet been implemented in the SITELLE ETC. You can contact the SITELLE instrument scientist ( if you need help or more details to prepare your justification using this new filter.

Time available The 2024B share of observing time is not firmly established yet. It is anticipated that during semester 24B, we will observe 50-100 hours for the Large Programs CLASSY and UNIONS. Those exact allocations have not been finalized. The allocations listed below assume that the associate partners, China and Taiwan, use all their available nights.

  • Canada: Approximatively 53 nights (outside the Large Programs)
  • France and Opticon:
    • Approximatively 49 nights (outside the Large Programs and Opticon allocation) for the CNRS PIs
    • CNRS allocated 4 to the Opticon ORP program through the OPTICON proposal system
  • University of Hawaii: Approximatively 22 nights (outside the Large Programs)
  • ASIAA: Up to 5 nights
  • NAOC: Up to 15 nights

During semester 24B, PI will have access to about 150 nights total. About half of the nights have the Moon illumination less or equal to 50% (Dark time), and half have the Moon illumination greater than 50% (Bright time). The dark time is split between MegaCam and SITELLE and the bright time between ESPaDOnS, WIRCam and SPIRou.

Technical notes [Up]

Start and end times (twilights) per instrument For time-constrained observations (such as transits with SPIRou), it may be important to consider the nightly start and end time for each instrument:

  • MegaCam and SITELLE: observing starts and ends at the 12deg twilights
  • WIRCam, ESPaDOnS, and SPIRou: observing starts and ends at the 8deg twilights

Important telescope limits

Please take into account the following operational constraints and ensure your proposal meets all of them:

ParameterLimit or constraintNote
MegaCam and SITELLE observationsbetween 12deg twilightsplease mention if observations need to wait for the 18deg twilight
WIRCam, ESPaDOnS and SPIRou observationsbetween 8deg twilights
Hour angle limits+/- 5h30
Airmass limit for MegaCam and WIRCam2.7622deg elevation limit
Airmass limit for SITELLE1.65
Declination limits for SITELLE-23deg to +63.5deg SITELLE cannot observe North of +63.5deg
Airmass limit for ESPaDOnS3.0observations can be performed up to an airmass of 4.0 if needed
Airmass limit for SPIRou2.5recommended limit to ensure the Image Quality remains good

Requested time Please ensure that the time requested in each proposal only includes the time requested from the agency selected (not the total time requested from all agencies concerned).

Please include in the time requested:

  • The integration time required to reach the necessary SNR. Please provide an example of the output of the ETC.
  • The overheads per exposure.
  • Time for on-sky calibrations not performed by CFHT.

Additional instructions for Canadian proposals [Up]

Multi-semester proposals CanTAC can recommend that CFHT schedule observing time for multiple semesters for snapshot or regular programs that require modest time allocations each semester. If you are interested in submitting a multi-semester program, please make a note of it in the Any other expenditure section of your proposal.

Anonymity of Canadian proposals The CanTAC requires that proposals be written in an anonymous fashion. CanTAC may choose to reject proposals they feel do not meet this criteria. Please refer to this article on Cassiopeia for more details and for tips and tricks about how to write anonymous proposals.

The anonymized proposals will consist of the Title, Abstract, Scientific Justification, Technical Justification, Instrument configuration, the list of targets and transit times (if applicable), the references and the link to other proposals. These sections will be given to CanTAC "as is". It is the responsibility of the proposers to ensure that they are written anonymously. Also, please insure that the uploaded pdf files do not include any identifying text in the headers of footers of the file.

The following fields will be removed from the anonymized proposals: PI and list of collaborators, Relevant previous allocations.

Snapshot programs [Up]

All agencies are invited to encourage their community to submit snapshot programs. These programs must be able to accept an Image Quality worse than 1.2" or significant levels of extinction. It is therefore recommended that IQ=1.2" be used and/or that some extinction be included when the Exposure Time Calculators are used. Snapshot programs are used not only during bad weather conditions but also to fill gaps in the queues when no A, B or C program are available or suitable. Snapshot programs are not counted toward an agency's allocation.

Good luck and clear skies!