The Upcoming 10 Years at CFHT


As CFHT approaches the end of the current Maunakea lease, we plan to spend the remainder of this decade working in close consultation with the newly formed Maunakea Stewardship and Oversight Authority (MKSOA), our Hawai'i community, and our astronomy community to build a collaborative future that we hope results in the continuation and upgrade of CFHT on Maunakea past 2033.

Based on our decades of experience and preparing for a bright future that includes MSE, CFHT proposed a streamlined instrumental and operational plan for the next 10 years. As agreed with CFHT's Scientific Advisory Council and Board of Directors, CFHT sought input from the user community on this plan. CFHT held two online discussions, in August and September 2023, during which we presented the plan and responded to questions and comments from the 80 or so participants. An anonymous survey was released in September, and highlights from the 158 responses received are presented below.


As seen from the highlights below, the survey mostly reached current users who are in their early to mid-career. The majority of respondents were from Canada, France, and UH, with a handful of reponses received from other past or current partners (Brazil, ASIAA, NAOC).

  • 63% of respondents are 5 years or more post-PhD
  • 77% have used CFHT in the past 5 years
  • By instrument used (the total exceeds 100% because some users use 2 or more instruments):
    • 37% have used ESPaDOnS
    • 37% have used MegaCam
    • 27% have used SPIRou
    • 25% have used WIRCam
    • 20% have used SITELLE
  • 35% of respondents are currently PI or co-I on a Large Program


VISION is an optomechanical interface that will allow installing SPIRou and ESPaDOnS at the Cassegrain focus of the telescope at the same time. Thanks to a beam splitter that will separate the near IR and optical beams without affecting polarization, and relay optics, VISION can be used to observe with SPIRou only (no intervening optics), or with ESPaDOnS only (using relay optics), or with both SPIRou and ESPaDOnS simultaneously (using the beam splitter).

The SAC report from May 2023 reaffirms its support for VISION.

Current CFHT users support VISION:

  • 37% of respondents to the survey have used ESPaDOnS and 27% have used SPIRou.
  • Among those who answered the question, there is roughly a 50/50 split on the question if VISION would be useful or not for them.
  • Some respondents indicated that while they will not use VISION for their science, they appreciate its scientific merit.
    • Decommissioning of WIRCam and SITELLE

      Based on a SAC recommendation from May 2023, CFHT proposes to decommission WIRCam and SITELLE by the end of 2026.

      • WIRCam is less interesting than SITELLE for CFHT users.
      • Users will miss SITELLE more than WIRCam.
      • Fewer users will submit a Large Program on WIRCam than on SITELLE.

      Large Programs

      As part of proposed streamlined operations, CFHT plans to offer more time to Large Programs. Our users seem in favor of having LP in general.

      • 62% of respondents say they will submit a Large Program proposal
      • 54% say the fraction of time for the Large Programs should be 25-50%, 28% say 50-75%

      Pathfinder IFU and MOS

      Pathfinder is an Integral Field Unit (IFU) and/or Multi-Object Spectrograph (MOS) instrument that will augment CFHT's scientific capabilities and futher development of the Maunakea Spectroscopic Explorer (MSE). For more details, please download the Pathfinder primer and the MSE primer.

      • For each of the 2 options, IFU and MOS, ~20-22% of respondents are likely or very likely to use it.
      • The interest for the Pathfinder is lower than the interest in VISION, however, the survey probed the interest of current CFHT users, which may not overlap with the community of users who are interested in Pathfinder.

      10-year plan (MegaCam + VISION + Pathfinder)

      The 10-year plan is based on the following context:

      • CFHT needs to reduce operating costs to match partner funding,
      • CFHT needs to find the best use of the funds provided by our agencies and partners to balance CFHT's scientific productivity,
      • and CFHT needs to keep MSE as the goal for CFHT's future.

      The proposed plan streamlines the operational workflow by:

      • implementing VISION by 2025,
      • decommissioning WIRCam and SITELLE by the end of 2026,
      • and increasing the fraction of Large Programs.

      The plan also includes a path to MSE, by:

      • designing, developing, and operating the Pathfinder instrument on CFHT, contigent on budget,
      • and advancing the MSE design.

      Users responded in the following way:

      • 64% of respondents are very likely or likely to apply for time with the proposed plan
      • 60% say CFHT should continue past 2033 with MegaCam + VISION + possibly Pathfinder