M.S. BESSEL (UBRRI PASSBANDS) - PASP 102, 1181-1199, October 1990 EFFECTIVE WAVELENGTH (A0V) U = 3659 A B = 4363 A V = 5448 A R = 6407 A I = 7982 A ZERO POINT (VEGA) U = 0.790 B = -0.102 V = 0.008 R = 0.193 I = 0.443