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Call for Proposals

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The Gemini Planet Imager (GPI) commissioning activities started in November 2013 and continue during the first semester of 2014. The commissioning is expected to be completed during the 2014B semester. Therefore, we invite the Gemini community to propose Early Science (ES) programs for GPI. Approximately six nights are available in April during the 2014A semester for this ES call.

Proposal submissions are due FRIDAY, FEBRUARY 28th, 2014, 23:59 UT .

The Early Science is way for the Gemini Community to get an early access to the instrument before it is offered in the 2014B semester. It is intended to be "end-to-end" testing, verifying the readiness of the entire system from observation preparation to data reduction. (The current version of the GPI IDL pipeline and data reduction package is now available from the instrument build team.) ES is also intended to exercise the instrument with a variety of observing programs and demonstrate to the community, through interesting and challenging science programs, the unique capabilities of GPI on Gemini South.

Commissioning is not yet complete, so performance information is preliminary and may not represent the final capability of GPI. All ES programs are undertaken in shared-risk mode. Updates will be provided as available on the GPI Status and Availability page, and notifications will be sent to the gpinews@gemini.edu mailing list, which is open to new subscribers.

Early Science proposals will be evaluated by the Gemini GPI Science Team including members from the Gemini Science and Technology Advisory Committee. Recommended programs will be forwarded to the Gemini Director for approval. Selection of ES programs will be done to ensure a wide range of types of target and observing modes. The different types of targets and approximate allocation times are given below. The allocated hours are notional only and will vary based on the programs selected. The proposed target observations must use the GPI Observing modes currently offered.

Available Observing Modes and approximate allocation times 
Observing Mode Allocated  science time
Coronography Y, J, H, K1 and K2 (IQ70CC50) 10 hours
Polarization Y, J, H, K1 and K2 (IQ70CC50) 10 hours
Direct Imaging or Polarization of Extended sources (i.e. any non-point source)  (IQ70CC50) 5 hours
Direct Imaging or Polarization with no accurate photometry needed (IQ85CC70) 10 hours
Non-sidereal(1) < 5 hours

(1) Observations of non-sidereal targets have been very limited to-date, so success of programs in this mode is uncertain.

The approved Early Science Principal Investigators will be responsible for providing written, in-depth assessments of ES observations within two months of data acquisition. The data obtained during ES will be made available to the international Gemini community after a two-month proprietary period, and information from the assessments of the ES teams will be published on the Gemini web pages. PIs of approved programs are strongly encouraged to provide manuscripts of results to Gemini in advance of publication, especially to allow staff to review technical performance of the instrument. Community participation will help to ensure that GPI is a success when the system is in regular use.

GPI is an extreme adaptive-optics imaging polarimeter/integral-field spectrometer, which will provide diffraction-limited data between 0.9 and 2.4 microns. The system will provide contrast ratios of 10^6 on companions at separations of 0.2-1 arcsecond in a 1-2 hour observation. The science instrument will provide spectroscopy or dual-beam polarimetry of any object in the field of view. Bright natural guide stars (I<9 mag) are required for optimal performance of the GPI adaptive optics system. GPI will be capable of detecting point sources down to H = 23 mag., with ≥ 5-sigma, in 1 hour (absent photon noise from a bright companion). For more information on achievable contrast, see the Contrast Page.


1. Target visibility: We expect to observe ES programs between April 20, 2014 and April 26, 2014. Therefore the targets should have RAs between 08 hours and 19 hours and Declinations between +10 degrees and -70 degrees (elevation > 45 degrees). Note that GPI OIWFS reaches its specifications for Zenith angles <30 degrees and it will work down to <50 degrees but with limited performance.

2. OIWFS Guide stars: GPI uses the science target for its AO correction and thus the science target must have a V magnitude brighter than 9 and not be extended objects to achieve the full expected Strehl.

3. Observing conditions constraints: The following constraints are allowed:

  • Image Quality(2): 70%-ile or 85%-ile.
  • Sky Transparency (cloud cover): photometric (50%-ile).
  • Sky Background: Any.
  • Sky Transparency (Water vapor content): Any.

(2) Reasonable corrections are possible under poorer image quality conditions (up to 1" natural seeing or IQ=85%-ile). Proposers that do not require high Strehl limited images are encouraged to submit targets for these conditions. Details about the contrast and Strehl ratios that could be achieved with GPI for different seeing conditions can be found in the GPI Strehl web page.

4. Target Duplication: The GPI Science Campaign target list is available here and any target duplication between the Campaign and any proposed target is subject to the Target Duplication Policy for GPI, which is available here.


To submit a program, use the 2014A Phase I tool and include observing constraints, target lists, and GPI Meta Mode configuration information. Be sure to select "Other Proposal Types" and "System Verification" in the Proposal Class and the Proposal Type fields respectively, inside the Scheduling and Time Request section of the Phase I Tool.

The overheads associated with a GPI science observation can be estimated using the information given in the Sensitivity and Overheads web page. Science time requests should include these overheads.


Scientific justification must be less than 1000 words. The technical justification should be sufficiently complete within its 1000 word limit that program feasibility can be assessed easily. A statement of data reduction plans must also be included in the technical justification. Proposers may use other data reduction tools in addition to the GPI IDL package. Selection for ES is based in part on the ability of the proposers to reduce the data and return feedback within a reasonable time.

By submitting an ES program the proposers agree to the following:

  • There is no guarantee that the program will be observed.
  • The proprietary period for ES data is two months.
  • The PI will provide reduced data to Gemini for public release within two months of the completion ES program.

The GPI astronomers will assist PIs of the successfully accepted programs to complete the Phase II.


February 5th Call for ES proposals
February 28th Phase I deadline
March 18th Announcement of selected programs
April 7th Phase II deadline
April 20th Start of Early Science run

Please, feel free to contact us with questions.


The GPI team

Contacts: Fredrik T Rantakyro (frantaky@gemini.edu) and Pascale Hibon (phibon@gemini.edu).

Gemini Observatory Participants