The Wide Field and Planetary Camera 2 (WFPC2) on HST is providing unsurpassed imaging capabilities and supporting accurate stellar photometry over large fields of view at high angular resolution. I discuss a feature of the WFPC2 CCD systems that nominally limits the dynamic range attainable with single exposures: a 12 bit analog to digital converter that does not allow sampling of the CCD full-well depth even at the low gain (14e-/DN) setting. I demonstrate that accurate stellar photometry can be performed on stellar images that are strongly saturated. Two 40 s exposures in V and I bands on the old open cluster M67 are analyzed to demonstrate photometric capabilities with a dynamic range of over 12 mag from single exposures. New photometric results for both bright and faint objects in M67 are derived from the WFPC2 data.
|Original language||English (US)|
|Issue number||1 PART 2|
|State||Published - Nov 1 1994|
All Science Journal Classification (ASJC) codes
- Astronomy and Astrophysics
- Space and Planetary Science