Compute etime,snr:10,sourcetype:pointsource,filter:Y,mAB:20,photometry:aperture,aperture:optimalaperture,sky:dark 0,airmass:1.2,transparency:1,seeing:0.7,etime: 11.25 ,radius: 0.53 ,flux frac: 60.72,obj sat: 4018.76 ,sky sat: 835.48