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ACS Anneal Dates

Anneal Dates

ACS Annealing

This page contains a listing of all past and future anneal dates for the ACS/WFC detector. As part of the CCD Hot Pixel Annealing calibration program, the ACS detector is periodically annealed in an attempt to slow the growth of hot pixels that arise from radiation damage. For each anneal, the thermoelectric coolers are shutdown and the heaters are powered on to warm the detector up to about 19ºC over the span of ~12 hours. Before and after each anneal, four 1040 second darks frames and 4 bias frames are taken for monitoring purposes to determine the efficiacy of the annealing process as the detector continues to degrade from radiation damage. 

  • Upcoming Anneal Windows for Cycle 30

    Sep 11, 2023 - Sep 17, 2023
    Oct 9, 2023 - Oct 15, 2023

Completed Anneals

Completed Anneals 

Note, this list of completed anneals only contains anneals occuring after Servicing Mission 4 (SM4) which occurred in May of 2009.


*The anneal originaly scheduled for June 23, 2021 was missed due to the HST safing on June 13, 2021.

Last Updated: 08/18/2023


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