NASA's James Webb Space Telescope

Guaranteed Time Observations Program

The Guaranteed Time Observations (GTO) program for the James Webb Space Telescope (JWST) is designed to reward scientists who helped develop the key hardware and software components or technical and inter-disciplinary knowledge for JWST. The observing time over the first three cycles will be allocated to these scientists, who include the:

  • Principal Investigators of the four science instruments (MIRI, NIRCam, NIRISS, and NIRSpec)
  • U.S. MIRI Science Lead and Science Team members
  • Six Interdisciplinary Scientists (IDS)
  • Telescope Scientist

Each GTO team submitted a description of the proposed Cycle 1 science program, with specific targets and observations. The proposals have been reviewed for duplication and adherence to allocations specified by NASA. The programs are organized by science topic, as follows:

  • Observations of Solar System Objects
  • Extra-solar Planets
  • Brown Dwarfs
  • Protostars, Protostellar Disks, and Young Stellar Objects
  • Debris Disks and Photodissociation Regions
  • Star Clusters, Star Formation Regions, Planetary Nebulae, and Galactic Transients
  • Targeted Galaxies
  • Clusters of Galaxies
  • High-redshift Quasars and Galaxy Assembly
  • Deep Fields

You can review the program information and observation specifications on the JWST User Documentation site.

Important Dates

Here are some important dates related to the GTO program.

Timeframe Event
January 6, 2017 Release of the Cycle 1 Call for GTO Proposals
April 1, 2017 Cycle 1 GTO Science Descriptions and Observation Specifications due
June 15, 2017 GTO Observation Specifications published 
July 28-November 15, 2017 GTO APT technical reviews and revisions
November 30, 2017 GTO APT Proposal submission complete
December 15, 2017 Public release of GTO APT files