Q:  By how many magnitudes in V-band did the object fade in 9 days?

 
           The measurements by Pian et al. show a fading by
                 delta = 6.2 magnitudes in 9 days


       What is this fading, expressed in intensity?

                I          -0.4*(6.2) 
              -----  =   10             =   0.0033   =    1/300
                I0