Gemini - Canada - Specific information for Phase I – 2023B


A call for proposals for Semester 2023B (August 1, 2023 to January 31, 2024) has been issued by the Gemini Observatory. The Call for Proposals can be viewed at: Call for Proposals

The deadline for the receipt of Canadian proposals is:

Deadline: Friday, March 31, 4 PM (Pacific Daylight Time)

Note: Not all Gemini partners have the same deadline, and those involved in joint proposals need to submit their proposals by the Principal Investigator (PI) country's deadline. Canada will have access in 2023A to a total time for PI programs of 206 hours on Gemini North and 151 hours on Gemini South.

Please consider submitting programs with relaxed observing conditions, suitable for Band 3, even if they will take longer to execute to get to the same S/N.


  • The instruments available on Gemini North are: GMOS-N, GNIRS and NIFS. NIRI is not offered. Altair is available in Natural Guide Star (NGS) and Laser Guide Star (LGS) mode for 2023A; only the LGS+P1 "Super-Seeing" mode is fully functional. Please check instrument webpages for updates on availability of full LGS. Visitor instruments offered on Gemini North, subject to demand: 'Alopeke and MAROON-X.
  • The instruments available on Gemini South are: GMOS-S, Flamingos-2 (imaging, long-slit and, now, MOS mode) and GSAOI with GeMs. The visitor instruments offered on Gemini South are Zorro and IGRINS.
  • Please consult the target accessibility page for important information concerning the right ascension (RA) restrictions for each instrument.

To see more details about each of the instruments available for 2023B, please see the Gemini Call for Proposals.

New in 2023B

  • Targets will generally be limited on Gemini North to 17 < RA hours < 13.5 and -37 < dec < +90, and on Gemini South to 16< RA hours < 12 and -90 < dec < +28. Please consult the target accessibility page for specific RA restrictions for some instruments in 2023B.
  • A special call for GHOST proposals is expected in the second half of the semester, using the Gemini South Fast Turnaround time. This will follow a System Verification program, with details to be advertised to the community when finalized.
  • A new grating B480 is available for GMOS-North. Please see all details here.
  • The replacement GMOS-South detector is expected to available from June 2023 onwards; check the instrument webpage for updates on availability.
  • Engineering shutdown periods are expected for both Gemini North and Gemini South during the 2023B semester: Gemini North from October 30 to November 03, 2023; Gemini South from September 25 to October 24, 2023. Note: These dates are provisional and may be subject to change.
  • Visitor instruments offered on Gemini North are:
    • 'Alopeke, a speckle camera. This is a dual-channel, fast-readout visual camera providing both diffraction-limited and wide-field imaging. Targets of Opportunity (Rapid or Standard) are accepted for 'Alopeke but will only be executed during the instrument blocks.
    • MAROON-X, a high-resolution (R=80,000) optical radial velocity spectrometer. The instrument has demonstrated sub m/s on-sky precision for RV measurements of M dwarfs.
  • Visitor instruments offered on Gemini South are:
    • Zorro, an 'Alopeke clone. Targets of Opportunity (Rapid or Standard) are accepted for Zorro but will only be executed during the instrument blocks.
    • IGRINS, a high-resolution R=45,000 near-IR (1.45 to 2.5 microns) echelle spectrometer. Please include the additional overheads for the science target acquisition and detector readout to your requested time.
  • There will be a minimum of 5 classical nights available on Subaru. If you apply for time through this Gemini time-exchange program, please also explicitly note if submitting a duplicate request through the Keck time-exchange program or the Subaru call for the same program. The instruments available are:
    • AO188 (LGS-AO with a shared-risk policy)
    • FOCAS
    • HDS
    • IRCS (LGS-AO available for the first time) and IRCS/SCExAO polarimetry mode available, also in shared-risk mode
    • MOIRCS
    • Hyper Suprime-Cam (HSC) now in queue mode. New filters are available but PIs must obtain prior approval for their use.
  • Subaru will also now accept shorter programs (less than 4 hours) for Subaru's Service mode, for IRCS, HDS, FOCAS or MOIRCS (imaging). Please indicate if you are requesting regular time (half night or full night) or service time (4 hours maximum including calibrations and overheads).
  • The following visiting instruments are also available for 2023B on Subaru. Proposals using the visiting instruments must include the relevant PI as a co-I.
    • SCExAO including the VAMPIRES module
    • CHARIS
    • IRD-Infrared Doppler, an infrared, high-resolution (up to 70000) fibre-fed spectrometer (as long as the targets are different from the approved SSP program)
    • REACH (IRD+SCExAO+AO188)
    • MEC in shared-risk mode
    • Fast PDI in shared-risk mode
    • NsIR waveplate unit
  • Warning: After submitting your proposal, you should see the status updated to "Successfully Received" in the Phase I Tool (PIT) "Submit" tab as well as a reference number for the proposal, such as "CA-2023B-003." If you do not see this reference number, the proposal might not have been received, and you are advised to contact

Other things to note

  • Canada, as well as other Gemini partners, have now moved to a dual-anonymous review process (DARP) for proposals. Please follow the DARP guidelines to write an anonymous proposal. This applies to all proposals, even those not led by a Canadian, so please make sure to warn your PI in that case.
  • In the PIT, there are now 2 attachments that are required to be filled and attached to the proposal: the first attachment will contain the science case, experimental design and technical justification; the second attachment will contain all the identifying sections, such as team information, previous use of telescope, publications, etc. This second part will not be shown to the referees and CanTAC members for their rankings.
  • The PIT now includes an option to specify in the "Time Requests" tab that the proposal is part of an AEON multi-telescope facility system proposal. A separate proposal must be sent to NOIRLab for the time requested on Las Cumbres and/or SOAR.
  • The PIT now also includes an option to specify in the "Time Requests" tab that the proposal has synergies with James Webb Space Telescope (JWST) observations. This is to encourage development of science programs that benefit from a combination of Gemini and JWST observations. It is not necessary to have already approved JWST time; it can relate to a future JWST proposal. In the science justification and experimental design sections, PIs should describe the science goals of the full Gemini and JWST program.
  • The PIT will automatically calculate the required time for baseline calibrations and add it to the time request. For each target you get from the Integration Time Calculator, enter the on-source exposure time needed with overheads (acquisition time, readout time, etc.), and the PIT will calculate the total time needed for the target.
  • Note: Because Gemini wishes to produce gender statistics to measure and monitor gender equality across the submitted and successful proposals, you are kindly asked to fill the gender field in the investigator details section of the PIT. This information will not be transmitted to CanTAC.
  • Classical mode observing is offered for facility instruments only. Priority Visitor mode is offered at both Gemini North and South. Users are encouraged to use the Remote Eavesdropping mode for all queue programs.
  • All proposals for Rapid Target of Opportunity (RToO) follow-up must submit a separate proposal for Standard Target of Opportunity follow-up (SToO) in conditions better than SB/CC/IQ=Any, if such follow-up is planned.
  • Poor weather and Director's Discretionary Time proposals can now be submitted at any time via the PIT directly to Gemini, bypassing CanTAC. Fast Turnaround proposals can be submitted at any time; the deadline is the end of every month.


Canadian astronomers must use the Gemini Observatory Phase I Tool (PIT) to prepare and submit their proposals. The new version of the PIT for Semester 2023B must be downloaded from the PIT installation site.

A new "Experimental Design" section has been added to give more space to the proposal description. The science justification, experimental design and technical justification are now to be entered in a .latex file (or .doc file if using the Windows version of the PIT). Also, the PIs are now strongly encouraged to include the output from the Instrument Time Calculators in the .pdf. See the PIT page to download the new PIT. Please download the .latex/.doc/.sty template files to write the proposal.

For Canadian proposals, please use the default GemPhase1_1_23B.tex, GemPhase1_2_23B.tex, gem-observing-proposal_23A.sty and GemPhase1_1_23B.docx and template files. Please allow extra time to familiarize yourself with the new PIT, be aware there are now 2 files to fill and append, and consult the help pages for the new PIT, which includes video tutorials.

In addition, please note that with the new PIT, a single proposal may now request time from either or both Gemini North and Gemini South (it is no longer necessary to submit 2 separate proposals, however, please indicate in the technical section how much time exactly is requested from each of Gemini North and South).

Users will submit their finalized proposals from the PIT; the proposals are sent electronically to Gemini and then retrieved by the Canadian Gemini Office (CGO). The CGO will be in charge of the technical assessment of the proposals, which will then be reviewed and ranked by CanTAC.

All data will be subject to the normal Gemini proprietary period of 12 months.

Proposal parameters

Please follow the instructions in the .latex/.doc files:

  • Scientific justification: 1 page (excluding references, see below)
  • Experimental design: 1 page
  • Technical justification: 1 page
  • Up to 2 extra pages for: references, a maximum of 3 figures and figure captions