CFHT Observation Proposals


The Call for proposal for the 2018B is now open.

The deadline for NRC and CNRS is March 20th 23:59 UTC
The deadline for ASIAA is March 20th 23:59 CST

CFHT adapted the Northstar Phase 1 tool written initially for the Radionet community. Northstar has been ported to CFHT and modified in house to handle our specific requirements. You can access the CFHT Phase 1 tool here during the call for proposals period or if you are interested in submitting a Director Discretionary time proposal.


If you are interested in applying for Gemini time through the CFHT-Gemini time exchange program, please follow this link.

Information on 2018B      [1 Aug 2018 - 31 Jan 2019]
Estimated time allocations
Approximate RA pressure from Large Programs.
Approximate availibility of bright and dark time.
Delay in reporting observation's metadata.
Gender neutrality of Canadian proposals.
SNR-QSO mode.
ETC values into PH1 proposal.
Snapshot programs.
WIRCam staring mode.
More details on Large Programs.

Estimated time allocations

The 2018B share of observing time is not firmly established yet. This allocation assumes that the associate partners, China and Taiwan, use all their available nights. This semester's allocation also takes into account commissioning and science verification time for SPIRou. Please note that the results from the 2018B-2022A call for Large Programs will only be known in mid-July 2018. Depending on the time allocated, the bar for the PI programs will have to be adjusted.

  • Canada: A minimum of 23 nights (outside the 2017-2019 Large Programs)
  • France and Opticon: A minimum of 21 nights (outside the 2017-2019 Large Programs). Of these 21 nights, 2 are offered to Opticon H2020 program through the OPTICON proposal system.
  • University of Hawaii: 15 nights (outside the 2017-2019 Large Programs).
  • Taiwan: Up to 10 nights.
  • China: Up to 15 nights.

  • It is important to note that SPIRou is not available for PIs during this round of call for proposals. It is only available for the call for Large Programs. Any PI program submitted for SPIRou in 2018B will be rejected.

    Approximate RA pressure from Large Programs.

    During the semester 2018B, the 2017A - 2019B and 2018B - 2022A Large Programs will be using the RA ranges in the table below. Please note the SPIRou LPs will start mid-2018B so the pressure on the bright time should be lower in the first half of the semester.

    Approximate availibility of bright and dark nights.

    During the semester 2018B, there are 95 dark nights available with the Moon illumination less or equal to 50%, and 89 bright nights when the Moon illumination is greater than 50%. The dark time is split between MegaCam and SITELLE and the bright time between ESPaDOnS, WIRCam and SPIRou. The 45 nights of dark time available to PIs corresponds to approximately 250h (average validated time), and the 42 nights of bright time correspond to approximatively 260h.

    The r-band portion of the CFIS Large Program requests IQ<0.8" and grey skies, whereas the u-band portion requests IQ<1" and dark skies. The VESTIGE Large Program requests IQ<1.2" and grey skies. PI programs targeting similar RA and at the same time requesting similar sky conditions will get into conflict with the Large Programs, decreasing the chance of getting observed.

    Delays in reporting your observation's metadata.

    In Recommendation 4 of the November 2017 meeting, SAC recommended that PIs have the option of requesting a delay in the reporting of the metadata with appropriate justification in their proposals. This can be done via Northstar by checking Yes to the Exception to the Community/World proprietary periods and metadata release in the Observing request tab and writing your justification in the box that appears. The metadata includes the name and coordinates of the targets. Unless the release date for the metadata is extended, they will become available immediately at CFHT and CADC.

    Gender neutrality of Canadians proposals.

    For Canadian proposals, the name of the PIs will be withheld from the proposals sent to the Canadian TAC to avoid gender bias issues. The proposal will instead list the name of the authors alphabetically. However, accepted proposals will be created under the PI's name as previously.

    SNR-QSO mode.

    SNR-QSO is now the default mode for MegaCam and ESPaDOnS and PIs who want to opt-out of this mode must justify it in their proposal. SAC recommendation #6 of the May 2016 report states: SNR-QSO should become the default mode for MegaCam and ESPaDOnS starting 2017A. Program requesting classical mode should justify their request.

    For more information about the SNR-QSO mode, please see the SNR-QSO web page.

    Other references to the SNR-QSO mode:
    • SPIE 2016 paper, Devost et al.
    • SF2A paper on Espadons by Moutou et al., section 2 covers SNR-QSO
    • ADASS 2013 paper, Cuillandre et al.
    • ETC values into PH1 proposal.

      The PH1 system has been changed to have users include the values of the exposure time calculators into their proposals. Proposals cannot be submitted if this field is not filled. This is not counted toward the page charge. Please include at least a representative set of ETC calculations with your proposal.

      Snapshot programs

      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. 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.

      WIRCam staring mode.

      For investigators interested in using the staring mode with WIRCam, please be advised that systematics may be present that limit the achievable accuracy using differential photometry. RMS values <= 0.1% are possible but reaching 0.01% is challenging. See Croll et al (2015) and Martioli et al (2017) for details. Also, experiments switching back and forth between two filters should be considered risky.

      More details on Large Programs.

      In 2018B, CFHT will be running the 2017A-2019B Large Programs as well as the 2018B-2022A Large programs.

      CFHT will flag any proposal which has conflicts in RA and observing conditions with an existing LP. For information about the relative priority of PI programs and Large programs, please see the recommendation from the SAC (Nov. 2009).

      Information on previous semesters
      If you wonder about the pressure on telescope time, the relative requests on the main instruments, you can have a look at some graphs for past rounds of proposals here.


      Good luck and clear skies!