Standard star outer atmosphere has magnitude mF= 5.00 observed using F filter, Within atmosphere star has count rate of 1122 counts/ seconds average at zenith distance 12 degrees and 675 counts/second at elevation z= 58 degrees Evaluate:

Show your work

a) Calculate the Atmospheric extinction coefficient, KF, at the wavelength of filter F?

b) An observation at z = 12 deg consisted of 8 quick sequential observations with exposure times of t = 8 sec for each 150,000 total counts when added, what is you conclusion if the standard deviation of the 8 sequential observations was 0.3mag (Note: background noise is not significant)? (please no hand writing solution for other wise down vote )