USNO Magnitudes versus calibrated

Field RA = 08h51.4m DC = +11°47'

Fig 1. USNO 'B' Magnitude Error f(Magnitude)
Red = USNO - Calibrated
Yellow = Best Fit: Y = +1.74 -0.124 * B_cal
Y vertical Tick = 0.1 magnitude
Offset for Magnitude 14.0 'B' = 0.00
Error cancels for Magnitude 14.0

Fig 2. USNO 'R' Magnitude Error f(Magnitude)
Red = USNO - Calibrated
Yellow = Best Fit: Y = +1.66 -0.106 * R_cal
Y vertical Tick = 0.1 magnitude
Offset for Magnitude 14.0 'R' = +0.18
Error cancels for Magnitude 15.7

For any comment, contact Jean-Claude PELLE