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Hubble Space Telescope
WFPC2 CTE Estimation Tool for Point Sources

This tool allows users of WFPC2 to estimate the effects of CTE losses on point sources. We have three tools on this page, based on three different publications. We believe the first one, the latest by Andrew Dolphin, to be the most accurate one.

CTE Tool #1

The correction formulae for this CTE tool were taken from Andrew Dolphin's website (09/17/2002 version), where they are described in detail (if this link does not work, here is an updated copy of Andy's webpage). Further information can also be found in the help file. The CTE loss is expressed in magnitudes. The input counts and background are expected in electrons.


CTE Tool #2

The correction formulae for this CTE tool were taken from Andrew Dolphin's website (05/31/2002 version), where they are described in detail; here is an updated local version of Andy's webpage. Further information can also be found in the help file. The CTE loss is expressed in magnitudes. The input counts and background are expected in electrons. This is the version used in the current WFPC2 Instrument Handbook.


CTE Tool #3

The correction formulae for this CTE tool were taken from Whitmore, et al., PASP, 1999, 111, 1559, and are shown in the help file. The corrected source counts are given in DN.


For detailed information on CTE and its effects, see: