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Phase I Overview

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Applications for time on Gemini are made through National Time Allocation Committees (NTACs) which are individually responsible for scientific and technical assessment and for making recommendations to the Gemini Observatory that time be awarded. Proposals will be solicited by Gemini every 6 months in early March and September; details of the submission and review process vary from Participant to Participant. Proposals for Large and Long Programs are accepted annually and assessed through a separate LP Time Allocation Committee. Proposals for Director's Discretionary Time can be submitted throughout the semester, and this time is open to all astronomers, independent of nationality. Poor weather proposals can also be submitted throughout the semester, and this time is open to users based in participating countries, the host institutions and Gemini staff. International collaborations ("joint proposals"), where time is being sought from several participating countries, must be submitted using the Gemini Phase I Tool (PIT) even if the proposal involves Participants that offer other submission mechanisms. The PIT supports automatic submission to multiple Participants at once. See the joint proposal instructions for more details.

Proposals from outside of the Gemini community must be submitted through one of the NTACs. Links to Participant- and host-specific information are contained in the following table.

us flag US Phase I info US Policies ca flag Canadian Phase I info Canadian Policies
arg flag Argentinean
Phase I info
Argentinean Policies br flag Brazilian
Phase I info
Brazilian Policies
ch flag Chilean
Phase I info
Chilean Policies Korea
Phase I info
Korean Policies
hi flag University of Hawaii Phase I info Proposals for University of Hawaii (UH) observing time on Gemini North must have a Principal Investigator affiliated with UH.

In normal operations, application may be made for classical or queue mode observations. Successful queue and classical applications are defined in advance using the Phase II Observing Tool. Classical mode observations are scheduled on specific dates and are carried out by the investigators visiting the telescopes. Queue mode observations are executed by the Gemini staff. This mode offers the potential of better matching observations to the prevailing conditions (e.g. image quality, sky background, cloud cover) and execution of Target of Opportunity observations for classes of targets whose coordinates are not known at the time of proposal submission. Gemini Observatory welcomes a variety of visiting scientists, including classical observers, queue investigators, students, and members of the National Gemini Offices.

The Phase I proposal submission process is supported by staff in the National Gemini Offices (NGOs). The Gemini Help Desk should be used to contact NGO staff regarding proposal submission. Technical instrument-specific advice is given in the "Observation Preparation" section of each of the Gemini instrument web pages. The worst possible weather conditions must be specified for each program. The Integration Time Calculators should be used to optimize your exposure time, conditions and signal to noise.

The NTAC results, comprising rank and recommended time awards, are sent electronically to Gemini Observatory. Each proposal is sent as an XML document consisting of attribute/value pairs that encode the proposal information together with a separate PDF file containing the science and technical case. The Gemini Phase I Tool (PIT) automatically generates the XML file. Participants who have chosen to use their own proposal system must translate their internal formats into the correct XML structures in order for the files to be ingested into the observing database. The NTAC and Staff forwarded proposals are merged together to produce a draft program queue at each telescope. For the merging to work effectively, the group of top-rated proposals that would fill that Participants share of the time available should contain a reasonable balance in terms of the observing constraints requested. The NTAC evaluations page lists various considerations for maximizing each Participant's use of their allocated time.

The International Time Allocation Committee (ITAC) consists of representatives from each NTAC and from Gemini Observatory. The merged queue and list of classical programs are considered by the ITAC, and duplications and conflicts are resolved. Observatory operations staff are consulted to ensure that programs can be scheduled; changes may be made to individual programs for schedulability. The recommended programs are forwarded to the Gemini Director for final approval. Approved programs are published on the Gemini public web pages, including: PI name, Participant country, proposal title and abstract, instrument.

Since Semester 18A, all programs in Band 1 (see exclusions below) 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", are treated equally with other Band 1s, whichever semester they are executing in. Time remaining in these programs is not removed per participant at ITAC as was the case with the previous formal Rollover system.

  • Exclusions: Classical, Fast-Turnaround, Large and Long, Director’s Discretionary, ToO, 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. 
  • Rollover programs previous to 18A: will be honored through their normal Rollover period. 

Scientific and technical feedback to the investigators about their proposal is generated by each NGO/NTAC. Notification of the award of time is generated by Gemini Observatory and sent to each investigator. NGOs then iterate with successful PI's to specify the Phase II observations. The formal handover of responsibility for supporting the investigators, from the NGO to Gemini Observatory, takes place upon transmission to Gemini of the final detailed Phase II program.

Gemini Observatory Participants