DAOFind + PSFPhotometry can conflict when masks are badly behaved #1802
Description
I got the following error:
ValueError: For one or more sources, the number of data points available to fit is less than the number of fit parameters. This could be due to a source(s) near the edge of the detector or if it has few unmasked pixels. Please check the input mask or source positions.
when using a mask for photometry. In this specific case, it's caused by this pixel:
(the background image is the boolean mask).
It would be a good idea to:
- add a mechanism to reject daofind-found stars with too few unmasked pixels
- skip such stars in fitting
- and/or, document that islands smaller than the number of free parameters should be excluded from masks.