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Call for Proposals Supporting Information

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This page contains information on the following topics relevant to applying for time on Gemini. The information is general in nature, for details specific to the upcoming semester, please see the current call for proposals. An overview of the Gemini proposal submission process is also available.

Time Allocation Process

An overview of the proposal submission and time allocation process is given here. The assessment and ranking of proposals within each partner country will be via National Time Allocation Committees (NTACs) supported by the National Gemini Offices. Assembly of the final semester schedule and queue, definition of scientific ranking bands and resolution of conflicts and joint proposals between partners is done by the International Time Allocation Committee (ITAC).

Submissions to Use Multiple Telescopes

A single proposal may request time from either or both of Gemini North and Gemini South. Hence a single proposal, with the same science goal, can request any combination of the instruments available at either telescope. Proposals for time on Subaru via the exchange program can only contain observations for Subaru. At the TAC stage, proposals for time on both Gemini North and South will be split into two proposals, to allow scheduling of each telescope independently. PIs should specify in detail in the technical case of the proposal how much time is needed at each telescope, per partner in the case of joint proposals; band 3 and minimum times should also be explicitly specified for each telescope.

"Persistent Band 1" Programs

Since Semester 18A, regular queue programs in Band 1 are allowed to execute over the full subsequent semester and encouraged to execute late in the semester before their formal allocation begins. These programs, designated "persistent Band 1", have Band 1 priority, whichever semester they are executing in.

  • Not included: Fast-Turnaround, Large and Long, Director’s Discretionary, Target of Opportunity and Limited-term partner programs do not persist across semester boundaries.
  • Best efforts: Programs using block scheduled instruments (e.g. Visitors, GPI, GSAOI) are extended on a strictly best-effort basis. 

Electronic Submission

All partners support electronic submission of proposals from within the Gemini Phase I Tool (PIT). Versions of the PIT are created for each semester, including new features described in PIT Hot News.

Joint Proposals

If you submit the same proposal to several partner countries a "joint proposal" you must do so using the PIT. The PIT software, and backend servers installed at each National Office, allow automatic ("one-click") submission of the same proposal to multiple partners. Joint proposals should be submitted by the deadline of the partner country to which the Principal Investigator is affiliated. The roles and contributions of each Partner Lead Scientist should be clearly explained in a Joint Proposal.

Under-Utilized Instruments

Community demand is a critical factor in determining instrument availability. Each instrument introduces significant overhead to the Observatory, and access to instrument ports is at a premium. If an instrument is requested for less than 6% of the Bands 1+2 time, the Observatory reserves the right to limit the RA range available to programs, or to not schedule the instrument.

Rapid Response or Target of Opportunity programs

We continue to encourage Target of Opportunity (ToO) programs, intended to allow observation of targets that cannot be specified in advance but which have a well defined external trigger (e.g., Supernovae or Gamma Ray Bursts which will be identified throughout the observing semester by non-Gemini programs). "ToO" mode may be requested with any facility instrument. Proposals for ToO mode should be made via the normal proposal process and must select the type of trigger in the PIT and summarise the trigger event (e.g. identification of a target brighter than a pre-determined threshold) in the proposal. Two types of ToO triggers are defined: "Rapid Response" and "Standard" which differ by response time. Rapid response programs must be allocated time in Band 1. ToO programs will not be given rollover status.

All proposals for Rapid Target of Opportunity (RToO) followup are required to submit a separate proposal for Standard Target of Opportunity followup (SToO) in conditions better than SB/CC/IQ=Any, if such followup is planned. Upgrades to good conditions will not be approved for RToO programs, and the SToO proposal is required if such conditions are necessary for later followup. This change is necessary for accurate filling of the queue, as ToO programs now make up a significant fraction of the Observatory band 1 time. See the Target of Opportunity (ToO) web page for further information.

GMOS Mask Definition

Mask making from non-GMOS images for GMOS multi-object spectroscopy (MOS) observations is available, but GMOS pre-imaging is recommended for MOS programs using slits narrower than 1.0" and for programs requiring very long observations of faint targets. If pre-imaging is required, then sufficient pre-imaging time should be included in the proposal. For classical programs, pre-imaging will be scheduled in the queue. Any unused pre-imaging time will be returned to the program.

Poor Weather Proposals

Often the queue contains insufficient proposals for the poorest conditions. Poor weather programs can be submitted to your NTAC at the time of the regular Call for Proposals, or at any time in the semester. Use the Phase I tool (PIT) to submit your proposal, selecting "Other" then "Poor Weather" as Proposal Class and Type respectively, in the PIT. "Poor Weather Queue" programs are placed in Band 4, and neither the PI nor partner country will be charged for any time used. Note however that poor weather programs are lower in priority than scientific ranking band 3. Poor weather programs may be submitted for any facility instrument but the observing constraints must match one of the following:

  • Image Quality of "any" and Cloud Cover of 70%-ile or worse (non-photometric)
  • Cloud Cover of "any" (more than one magnitude of cloud cover and unusable in the mid-IR) and any other combination of conditions

Water Vapour constraints for all poor weather proposals need to be set to "any". The Sky Background constraint can be specified and it is acceptable for these programs to request dark time.

Exchange Time

Gemini Observatory encourages exchanges with other major observatories in order to expand the instrument capabilities available to the Gemini community. At present, the Observatory has an exchange program with Subaru Observatory. The details of the amount of time currently available and other restrictions are provided in the current call for proposals. PIs in the Gemini community who intend to use the Subaru telescope are encouraged to apply through the time-exchange program and not through the ordinary Subaru Call for Proposals. Similarly, Subaru request that those with direct access to Gemini not request time on Gemini via the Subaru exchange program.

Target Information

Time-specific (including periodic monitoring and follow-up) programs may be accepted on a best-efforts basis. Proposers should specify these time constraints in the PIT. Note that the instrument scheduling may impose additional restrictions on this class of programs.

All observations require the use of one wavefront sensor (WFS) star for fast guiding, primary mirror active optics control and/or as an adaptive optics wavefront reference source. The specific requirements for each instrument are given in the relevant science instrument web pages. Target of Opportunity programs do not need to define WFS stars. The Phase 1 Tool will indicate the probability of there being a suitable WFS star for each observation. If the probability is low, then the target, conditions or configuration should be changed to allow guiding. Non-sidereal tracking is available for all instruments. Non-sidereal tracking with GMOS is fully supported with the peripheral wavefront sensors and partially supported with the OIWFS.

Duplicate Observations

Proposers should check their observations against the Gemini Science Archive to ensure that similar observations have not already been executed. The Phase I Tool will automatically search the Archive and indicate whether duplicates are found. If they are, clicking on the icon in the lower right of the Observations section of the tool will list the data found. Any duplicate or seemingly duplicate observations should be well-justified in the proposal. The NTACs will consider duplication of existing observations as part of the proposal evaluation. The ITAC evaluates and resolves any duplication of targets (or potential duplication in the case of ToO observations) between proposals from different partner countries.

Gemini Observatory Participants