[Previous] | [Session 36] | [Next]
I. Heyer, S. Baggett, S. Gonzaga, J. A. Biretta (STScI), WFPC2 Photometry Team
We examine the WFPC2 stellar photometric monitoring data obtained over the last four years. The new analysis shows that, for bright targets, (1) the long-term photometric throughput continues to be quite stable: fluctuations are ~2% or less peak-to-peak over 4 years in filters longwards of and including F336W, (2) the UV throughput has gradually evolved, that is, the clean count rates (immediately after the decons) have increased over the 4 years in some filters, e.g., F160BW by ~12% in the PC, and F170W by ~9%, while decreasing slightly in others, e.g., F255W by ~3% and, (3) the contamination growth rates have slowed slightly for the UV filters, e.g., ~1% per day to 0.5% per day in F160BW on the PC. The small discontinuity around Feb. 1995 is discussed. These results have been used to update the WFPC2 time-dependent photometric calibration within SYNPHOT.
If you would like more information about this abstract, please follow the link to http://www.stsci.edu/ftp/instrument_news/WFPC2/wfpc2_site.html. This link was provided by the author. When you follow it, you will leave the Web site for this meeting; to return, you should use the Back comand on your browser.