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JWST Interactive Sensitivity Tool

Screenshot of the JWST Interactive Sensitivity Tool (JIST) interface.

JIST uses a pre-calculated grid of ETC calculations to quickly estimate sensitivities and exposure times in a responsive, interactive plot, and indicates when your observation might saturate. 

JIST offers a restricted view of the full JWST ETC parameter space, and assumes:

  • A single flat-spectrum (in Fnu) point source.
  • A single standard background spectrum corresponding to 1.2 times the minimum zodiacal background.
  • ETC defaults for all other parameters.

Finally, most, but not all, science modes are available in JIST.

After using JIST to make your initial estimates, you are invited to use the JWST ETC to craft your proposal.


JIST       User Documentation (JDox)



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For technical assistance, please contact the JWST Help Desk.


The NASA James Webb Space Telescope, developed in partnership with ESA and CSA, is operated by AURA’s Space Telescope Science Institute.