CFHT Observation Proposals

The CFHT call for proposals for 2016B is now closed

The Call for proposal for the 2017A semester will open around August 20th 2016.

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.

Information on 2016B      [1 Aug 2016 - 31 Jan 2017]

Estimated time allocations

The 2016B share of observing time is not firmly established yet. It should not differ by more than a few nights from the following numbers:
  • Canada: up to 34 nights (outside the 2013-2016 Large Programs)
  • France and Opticon: up to 20 nights (outside the 2013-2016 Large Programs). Of these 20 nights, 5 Nights are offered to Opticon through the OPTICON proposal system.
  • University of Hawaii: Up to 19 nights
  • Taiwan: up to 8 nights (2 nights are allocated to LPs)
  • Brazil: up to 9 nights (1 night is allocated to LPs)
  • China: up to 12 nights (3 nights allocated to a multisemester program).

  • RA pressure from Large Programs.

    Please note that during the semester 2016B, Large Programs will be using the following RA ranges:
    • OSSOS on MegaCam : 70hrs for RA=00-04h
    • CFHT LUAU on MegaCam: 14 hrs for RA=16-20h, 46 hrs for RA=20-24h, 40 hrs for RA=0-4h. All the 100 allocated hours are dark time.
    • Matysse on ESPaDOnS: 72hrs for RA=04-08h
    • Binamics on ESPaDOnS: TBD.
    • HMS on ESPaDOnS: 2.91hrs for RA=08-12h, 60.37hrs for RA=4-8h and 64.96 for RA=0-4h.


    CFHT is accepting SITELLE proposals for the 2016B semester. You will find details on the instrument as well as a link to the ETC in the SITELLE home page. If you have any questions about the instrument, please contact Daniel Devost (

    Dark and bright time availability.

    We encourage our users to submit bright time proposals for the 16B semester. Dark time on MegaCam and SITELLE was heavily oversubscribed in 16A and we had an undersubscription of bright time programs. For 2016B, an average of 568 hours of dark time (moon down) will be available for PI programs asking for MegaCam and SITELLE and an average of 603 hours of bright time will be available to PIs requesting ESPaDOnS and WIRCam.

    MegaCam filters

    All the new filters for MegaCam will be available for 2016B. Programs should use the new filter set. A strong scientific case must be made in the proposal for the need of the old filters. Recommendation #5 of the may 2015 SAC report states: SAC recommends that the filter selection offered to MegaCam users be rationalized. Programs should use the new filter set, unless a strong scientific case is made in the proposal for the need of the old filters. SAC also recommends that the old filters be decommissioned in the medium-term and not available in semester 17A and beyond. The CFHT user community should be informed of this policy before the 16A proposal call.

    New PH1 rule.

    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.

    Exposure time calculators.

    A feature has been added to the MegaCam and WIRCam ETC: there is now a galaxy profile mode, in addition to the previous point-source and extended source modes. This new mode corresponds to galaxies more extended than a point-source, but where the seeing still matters. The galaxy profile itself is based on Sersic profiles with indices varying from 1 (exponential disks) to 5 (4 corresponds to de Vaucouleurs’ profiles, typical of elliptical galaxies). The width of this profile is settled by the half-light radius, given in arcsec. The galaxy profile is then convolved with the seeing profile to make the exposure time or signal-to-noise ratio computations. This new feature is intended to replace the “galaxy" choice in the previous ETC. For larger galaxies where the seeing does not matter, you can either use the galaxy mode with a large half-light radius, or the extended source mode if you plan to reach a given surface brightness in the outskirts of the galaxy. Should a replacement for the previous “nearby galaxy” mode be needed, we can easily add it in the future. See the ETC web pages of each instrument for details.

    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. (AJ, 141:30, 2011) for details. Also, experiments switching back and forth between two filters should be considered risky.

    For information about the relative priority of PI programs and Large programs, please see the recommendation from the SAC (Nov. 2009).

    A new set of Large Programs has been accepted starting 2015A. CFHT will flag any proposal which has conflicts in RA and observing conditions with an existing LP. See the SAC recommendation (May 2014).

    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!