7. Run fistar on all stitched k2mosaic files --- use an optimal flux threshold value (I used 50)
fistar -i /Volumes/Seagate_Expansion/NGC6819/k2mosaic/q04ch78/k2mosaic-q04-ch78-cad12304.fits -o /Volumes/Seagate_Expansion/NGC6819/IMG/q04ch78/q04-ch78-cad12304.fistar -s flux --comment --model elliptic --flux-threshold 5 --algorithm uplink --iterations symmetric=2,general=1 --format id,x,y,bg,amp,flux,s/n,fwhm --only-candidates