Compute
etime,snr:10,sourcetype:pointsource,filter:u,mAB:20,photometry:aperture,aperture:optimalaperture,sky:dark
0,airmass:1.2,transparency:1,seeing:0.7,etime: 2.67 ,radius: 0.59 ,flux
frac: 67.36,obj sat: 11953.68 ,sky sat: 161814.81