11274(  1) - 03/30/07 11:22  - [  1]

                  HUBBLE SPACE TELESCOPE OBSERVING PROGRAM 11274

Version: 1    Check-in Time: 30-Mar-2007 15:22:22       STScI Edit Number: 0

Title
A Final Calibration of the Primary WFPC2 Emission-Line Filters Using the Orion
Nebula
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Type             Cycle     Parallel Pointing Tolerance
AR               16        <none>
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Investigators
                                                                                     Contact?
    PI: Dr. C. Robert O'Dell              Vanderbilt University

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Abstract

Emission-line imaging with the WFPC2 has been dominated by use of the F656N, F 658N,
and F502N filters.These filters require on-orbit calibration in order to convert
their signals to absolute energy surface brightness units. This has previously been
done, but there is a question of time variation of their properties and this will be
addressed by special observations of the Orion Nebula as part of calibration program
11038. This archive program will use the previously adopted method that uses a well-
calibrated long-slit reference sample to calibrate the data. There is also a mid-
lifetime set that will allow tracking variations with time. I will also determine if
a new set of multi-aperture groundbased data is satisfactory for use as a reference
source and if it is, to determine variations in the calibration constants across the
individual CCD detectors and with better time resolution by using five additional
studies.
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