USNO Magnitudes versus calibrated

Field RA = 05h57.8m DC = +00°15'

Fig 1. USNO 'B' Magnitude Error f(Magnitude)
Red = USNO - Calibrated
Yellow = Best Fit: Y = -0.24 -0.011 * B_cal
Y vertical Tick = 0.1 magnitude
Offset for Magnitude 14.0 'B' = -0.39
Error cancels for Magnitude -21.2

Fig 2. USNO 'R' Magnitude Error f(Magnitude)
Red = USNO - Calibrated
Yellow = Best Fit: Y = +0.61 -0.028 * R_cal
Y vertical Tick = 0.1 magnitude
Offset for Magnitude 14.0 'R' = +0.22
Error cancels for Magnitude 22.0

For any comment, contact Jean-Claude PELLE