Release Notes for ETC 25.1.1

This patch release resolves the following known issues:

WFC3: —

  • The background is now correctly computed for the UVIS grism G280.
  • The source and background flux are now correctly computed for the UVIS quad filter FQ937N even when the wrong chip (2) is selected.

Release Notes for ETC 25.1

New Features

Welcome to ETC 25.1. This version of the ETC implements a few new features, notably:


  • Nothing to report.


  • Nothing to report.


  • Improved descriptions of ACQ modes on COS Spectroscopic Acquisition ETC
  • Calibration warning has been added for NUV calculations with COS Spectroscopic ETC


  • An additional option has been added in Question 1 for the CCD detector. It allows users to specify the level of additional detector background rate that should be assumed in the calculation, with the [low, medium, high] settings corresponding to the [top, middle, bottom] of the detector, respectively.


  • Nothing to report.


  • The wording of various sections of the user’s guide has been improved for clarity.

Under the hood

  • Instrument data values and/or detector sensitivity values have been updated for COS, STIS, and WFC3 UVIS. (No updates were necessary for WFC3 IR.)
  • Error messages have been improved for the rare cases where input specifications
cannot be supported by enclosed energy tables

Resolved Issues

This version does not resolve any known issues.

Known Issues

Please see the News and Known Issues page for known issues with this release.


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