Spitzer Documentation & Tools

IRAC High Precision Photometry

Until recently data has mostly been taken with 0.1, 0.4, or 2s exposure times.  As researchers push to fainter and fainter targets, observations have started to be taken with longer frame times.  What happens when we do staring mode observations at longer frame times, such as 12, 30, and 100s?

One concern is that the intrapixel gain effect will get smeared out as the exposure times will be long compared with the timescales of spacecraft motion.  While the IRAC team has not done a complete analysis of this, we are hearing anecdotal evidence that 12 and 30s are resonable to use with current best practices.  It is unclear what the systematics will look like with 100s exposure times.