Release Notes for ETC 29.2

New Features

Welcome to ETC 29.2, released in June 2021.

This version includes data updates and a new COS warning concerning use of the G285M grating.


  • The ETC evaluation date remains 2022-Apr-01 (MJD 59670)

  • There were minor corrections to several Phoenix models (HETC-502)


  • ACS/SBC imaging modes sensitivity updated with measurements taken on 2021 Apr 03. (HETC-498)

  • ACS/SBC dark rate updated to 8.52e-6 counts/sec. Measurements taken 2021 Mar 01. (HETC-498)


  • Updated Time-Dependent Sensitivity (TDS) slopes were obtained for the FUV standard modes and the NUV modes, and new TDSTAB and synphot files were delivered. This resulted in small changes in the throughput for these modes. (HETC-499)

  • Dark rates for FUV and NUV were updated and changed by up to a few percent. (HETC-499)

  • A new warning has been added to the COS ETCs to advise the user against the use of G285M.


  • No change


  • Throughput files for both UVIS and IR modes change slightly for most filters. There are changes of 10% to 20% for the UVIS quad filters FQ232N, FQ243N, FQ575N, FQ672, and FQ674N, but the calibrations are based on a limited set of observations and have large uncertainties. (HETC-501)


  • Added a brief section to the user’s guide on the WFC3 scan mode (HETC-501)

Under the Hood

  • Pysynphot remains at 0.9.14, which includes Vega normalization with the v008 CALSPEC model

Resolved Issues


Known Issues

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


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