Gemini - Canadian - Specific information for phase I – 2023A


A call for proposals for Semester 2023A (February 1, 2023 to July 31, 2023) 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, September 30, 4 pm (Pacific Daylight Time)

Note that not all Gemini partners have the same deadline and those involved in joint proposals need to submit their proposals by the principal investigator's (PI) country's deadline. Canada will have access in 2023A to a total time for PI programs of: 199 hours on Gemini North, and 161 hours on Gemini South.

Please consider submitting programs with relaxed observing conditions too, suitable for Band3, 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, NIRI (imaging only) and NIFS. Altair is available in Natural Guide Star and Laser Guide Star mode for 2023A. Many visitor instruments will also be offered on Gemini North, subject to demand: GRACES, 'Alopeke and MAROON-X.
  • The instruments available on Gemini South are: GMOS-S, Flamingos-2 (imaging,longslit, and now MOS mode too), 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 RA (right ascension) restrictions for each instrument.

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

What's new in 2023A

  • Canada, as well as many other Gemini partners, has now moved to a dual-anonymous review process (DARP) for proposals for this semester 2023A. 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 PIT there are now TWO attachments that are required to be filled and attached to the proposal in PIT: one attachment will contain the science case, experimental design and technical justification; the second one 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.
  • 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.
  • PIT now also includes an option to specify in the 'Time Requests' tab that the proposal has synergies with 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+JWST program.
  • Targets will generally be limited on Gemini North to 4 < RA < 1 and -37 < dec < +90, and on Gemini South to 5 < RA < 1 and -90 < dec < +28. Please consult the target accessibility page for specific RA restrictions for some instruments.
  • A new low-resolution IFU is being commissioned in GNIRS and will be offered for Fast Turnaround proposals only in 2023A.
  • A new grating B480 is available for GMOS-South. Please see all details here.
  • Visitor instruments offered on Gemini North are:
    • GRACES, the high-resolution R=67500 optical spectrometer;
    • '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 do NOT double-dip by also applying through the Keck time-exchange program or the Subaru call for the same program. The instruments available are:
    • AO188 (but no LGS-AO)
    • FOCAS
    • HDS
    • IRCS
    • 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 SWIMS. Please indicate if you are requesting regular time (half night or full night) or service time (4hours maximum including calibrations and overheads).
  • The following visiting instruments are also available for 2023A on Subaru. Proposals using the visiting instruments must include the relevant PI as a co-I.
    • SCExAO including the VAMPIRES module
    • CHARIS
    • SWIMS, a wide-field near IR imager and multi-object spectrograph
    • 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)
    • MEC in shared-risk mode
    • Fast PDI in shared-risk mode
    • NsIR waveplate unit
  • Warning: when submitting your proposal, you should see in the PIT "Submit" tab the status updated to "Successfully Received", and see a reference number for the proposal, such as "CA-2023A-003". If you do not see this reference number then the proposal might not have been received, and you are advised to please check with us at

Other things to note for 2023A

  • The PIT will automatically calculate the required time for baseline calibrations and add it to the time request. Just enter for each target the on-source exposure time needed WITH overheads (acquisition time, readout time, etc.) for each target that you get from the ITC, and PIT will calculate the total time needed for the target.
  • Note that 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 PIT. This information will not be transmitted to CanTAC
  • The Classical mode will not be offered for semester 2023A. 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 PIT directly to Gemini (bypassing the Canadian Time Allocation Committee (CTAC)). Fast Turnaround proposals can be submitted at all times with a deadline at 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 PIT for Semester 2023A 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 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_23A.tex, GemPhase1_2_23A.tex, gem-observing-proposal_23A.sty and GemPhase1_1_23A.docx and template files. Please allow extra time to familiarize yourself with the new PIT, be aware there are now TWO 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 of 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 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 CTAC.

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