Differential atmospheric refraction at the NOT as a function of wavelength (horizontal, in Angstrom) and airmass (vertical), for T = 20 deg, R.H. = 10 %, Pressure = 775 mbar. The values are in arcseconds with respect to a wavelength of 5000 Angstrom 3000 3500 4000 4500 5000 5500 6000 6500 7000 7500 8000 8500 9000 9500 10000 Sec Z 1.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 1.05 0.63 0.35 0.19 0.08 0.00 -0.06 -0.10 -0.13 -0.16 -0.18 -0.19 -0.21 -0.22 -0.23 -0.24 1.10 0.90 0.51 0.27 0.11 0.00 -0.08 -0.14 -0.19 -0.23 -0.25 -0.28 -0.30 -0.32 -0.33 -0.34 1.15 1.11 0.63 0.33 0.14 0.00 -0.10 -0.18 -0.23 -0.28 -0.32 -0.35 -0.37 -0.39 -0.41 -0.42 1.20 1.30 0.74 0.39 0.16 0.00 -0.12 -0.20 -0.27 -0.33 -0.37 -0.40 -0.43 -0.46 -0.48 -0.49 1.25 1.47 0.83 0.44 0.18 0.00 -0.13 -0.23 -0.31 -0.37 -0.42 -0.46 -0.49 -0.52 -0.54 -0.56 1.30 1.62 0.92 0.49 0.20 0.00 -0.15 -0.26 -0.34 -0.41 -0.46 -0.51 -0.54 -0.57 -0.60 -0.62 1.35 1.77 1.01 0.53 0.22 0.00 -0.16 -0.28 -0.37 -0.45 -0.50 -0.55 -0.59 -0.62 -0.65 -0.68 1.40 1.91 1.09 0.58 0.24 0.00 -0.17 -0.30 -0.40 -0.48 -0.54 -0.60 -0.64 -0.67 -0.70 -0.73 1.45 2.05 1.16 0.62 0.25 0.00 -0.19 -0.32 -0.43 -0.52 -0.58 -0.64 -0.68 -0.72 -0.76 -0.78 1.50 2.19 1.24 0.66 0.27 0.00 -0.20 -0.35 -0.46 -0.55 -0.62 -0.68 -0.73 -0.77 -0.80 -0.83 1.55 2.31 1.31 0.70 0.29 0.00 -0.21 -0.37 -0.49 -0.58 -0.66 -0.72 -0.77 -0.82 -0.85 -0.88 1.60 2.44 1.38 0.73 0.30 0.00 -0.22 -0.39 -0.51 -0.61 -0.69 -0.76 -0.81 -0.86 -0.90 -0.93 1.65 2.57 1.46 0.77 0.32 0.00 -0.23 -0.41 -0.54 -0.64 -0.73 -0.80 -0.86 -0.90 -0.94 -0.98 1.70 2.69 1.52 0.81 0.33 0.00 -0.24 -0.42 -0.56 -0.68 -0.76 -0.84 -0.90 -0.95 -0.99 -1.02 1.75 2.81 1.59 0.84 0.35 0.00 -0.25 -0.44 -0.59 -0.71 -0.80 -0.87 -0.94 -0.99 -1.03 -1.07 1.80 2.93 1.66 0.88 0.36 0.00 -0.26 -0.46 -0.61 -0.74 -0.83 -0.91 -0.98 -1.03 -1.08 -1.12 1.85 3.04 1.73 0.91 0.38 0.00 -0.27 -0.48 -0.64 -0.76 -0.87 -0.95 -1.02 -1.07 -1.12 -1.16 1.90 3.16 1.79 0.95 0.39 0.00 -0.28 -0.50 -0.66 -0.79 -0.90 -0.98 -1.05 -1.11 -1.16 -1.20 1.95 3.27 1.86 0.98 0.41 0.00 -0.29 -0.52 -0.69 -0.82 -0.93 -1.02 -1.09 -1.15 -1.20 -1.25 2.00 3.39 1.92 1.02 0.42 0.00 -0.31 -0.53 -0.71 -0.85 -0.96 -1.05 -1.13 -1.19 -1.25 -1.29 2.05 3.50 1.98 1.05 0.43 0.00 -0.32 -0.55 -0.74 -0.88 -1.00 -1.09 -1.17 -1.23 -1.29 -1.33 2.10 3.61 2.05 1.09 0.45 0.00 -0.33 -0.57 -0.76 -0.91 -1.03 -1.12 -1.20 -1.27 -1.33 -1.38 2.15 3.72 2.11 1.12 0.46 0.00 -0.34 -0.59 -0.78 -0.94 -1.06 -1.16 -1.24 -1.31 -1.37 -1.42 2.20 3.83 2.17 1.15 0.47 0.00 -0.35 -0.60 -0.81 -0.96 -1.09 -1.19 -1.28 -1.35 -1.41 -1.46 2.25 3.94 2.23 1.18 0.49 0.00 -0.36 -0.62 -0.83 -0.99 -1.12 -1.23 -1.31 -1.39 -1.45 -1.50 2.30 4.05 2.30 1.22 0.50 0.00 -0.36 -0.64 -0.85 -1.02 -1.15 -1.26 -1.35 -1.43 -1.49 -1.54 2.35 4.16 2.36 1.25 0.51 0.00 -0.37 -0.66 -0.87 -1.05 -1.18 -1.29 -1.39 -1.46 -1.53 -1.59 2.40 4.26 2.42 1.28 0.53 0.00 -0.38 -0.67 -0.90 -1.07 -1.21 -1.33 -1.42 -1.50 -1.57 -1.63 2.45 4.37 2.48 1.31 0.54 0.00 -0.39 -0.69 -0.92 -1.10 -1.24 -1.36 -1.46 -1.54 -1.61 -1.67 2.50 4.48 2.54 1.35 0.55 0.00 -0.40 -0.71 -0.94 -1.13 -1.27 -1.39 -1.49 -1.58 -1.65 -1.71 2.55 4.58 2.60 1.38 0.57 0.00 -0.41 -0.72 -0.96 -1.15 -1.30 -1.43 -1.53 -1.62 -1.69 -1.75 2.60 4.69 2.66 1.41 0.58 0.00 -0.42 -0.74 -0.99 -1.18 -1.33 -1.46 -1.57 -1.65 -1.73 -1.79 2.65 4.80 2.72 1.44 0.59 0.00 -0.43 -0.76 -1.01 -1.21 -1.36 -1.49 -1.60 -1.69 -1.77 -1.83 2.70 4.90 2.78 1.47 0.61 0.00 -0.44 -0.77 -1.03 -1.23 -1.39 -1.53 -1.64 -1.73 -1.80 -1.87 2.75 5.01 2.84 1.51 0.62 0.00 -0.45 -0.79 -1.05 -1.26 -1.42 -1.56 -1.67 -1.76 -1.84 -1.91 2.80 5.11 2.90 1.54 0.63 0.00 -0.46 -0.81 -1.07 -1.29 -1.45 -1.59 -1.71 -1.80 -1.88 -1.95 2.85 5.22 2.96 1.57 0.65 0.00 -0.47 -0.82 -1.10 -1.31 -1.48 -1.62 -1.74 -1.84 -1.92 -1.99 2.90 5.32 3.02 1.60 0.66 0.00 -0.48 -0.84 -1.12 -1.34 -1.51 -1.66 -1.78 -1.87 -1.96 -2.03 2.95 5.42 3.08 1.63 0.67 0.00 -0.49 -0.86 -1.14 -1.36 -1.54 -1.69 -1.81 -1.91 -2.00 -2.07 3.00 5.53 3.14 1.66 0.68 0.00 -0.50 -0.87 -1.16 -1.39 -1.57 -1.72 -1.84 -1.95 -2.03 -2.11 3.05 5.63 3.19 1.69 0.70 0.00 -0.51 -0.89 -1.18 -1.42 -1.60 -1.75 -1.88 -1.98 -2.07 -2.15 3.10 5.73 3.25 1.72 0.71 0.00 -0.52 -0.91 -1.21 -1.44 -1.63 -1.79 -1.91 -2.02 -2.11 -2.19 3.15 5.84 3.31 1.76 0.72 0.00 -0.53 -0.92 -1.23 -1.47 -1.66 -1.82 -1.95 -2.06 -2.15 -2.23 3.20 5.94 3.37 1.79 0.74 0.00 -0.54 -0.94 -1.25 -1.49 -1.69 -1.85 -1.98 -2.09 -2.19 -2.27 3.25 6.04 3.43 1.82 0.75 0.00 -0.54 -0.95 -1.27 -1.52 -1.72 -1.88 -2.02 -2.13 -2.22 -2.30 3.30 6.15 3.49 1.85 0.76 0.00 -0.55 -0.97 -1.29 -1.55 -1.75 -1.91 -2.05 -2.17 -2.26 -2.34 3.35 6.25 3.54 1.88 0.77 0.00 -0.56 -0.99 -1.31 -1.57 -1.78 -1.95 -2.09 -2.20 -2.30 -2.38 3.40 6.35 3.60 1.91 0.79 0.00 -0.57 -1.00 -1.34 -1.60 -1.81 -1.98 -2.12 -2.24 -2.34 -2.42 3.45 6.45 3.66 1.94 0.80 0.00 -0.58 -1.02 -1.36 -1.62 -1.84 -2.01 -2.15 -2.27 -2.37 -2.46 3.50 6.56 3.72 1.97 0.81 0.00 -0.59 -1.04 -1.38 -1.65 -1.87 -2.04 -2.19 -2.31 -2.41 -2.50 3.55 6.66 3.78 2.00 0.82 0.00 -0.60 -1.05 -1.40 -1.67 -1.89 -2.07 -2.22 -2.35 -2.45 -2.54 3.60 6.76 3.83 2.03 0.84 0.00 -0.61 -1.07 -1.42 -1.70 -1.92 -2.11 -2.26 -2.38 -2.49 -2.58 3.65 6.86 3.89 2.06 0.85 0.00 -0.62 -1.08 -1.44 -1.73 -1.95 -2.14 -2.29 -2.42 -2.52 -2.62 3.70 6.96 3.95 2.09 0.86 0.00 -0.63 -1.10 -1.46 -1.75 -1.98 -2.17 -2.32 -2.45 -2.56 -2.66 3.75 7.06 4.01 2.12 0.87 0.00 -0.64 -1.12 -1.49 -1.78 -2.01 -2.20 -2.36 -2.49 -2.60 -2.69 3.80 7.16 4.06 2.15 0.89 0.00 -0.65 -1.13 -1.51 -1.80 -2.04 -2.23 -2.39 -2.52 -2.64 -2.73 3.85 7.27 4.12 2.18 0.90 0.00 -0.66 -1.15 -1.53 -1.83 -2.07 -2.26 -2.42 -2.56 -2.67 -2.77 3.90 7.37 4.18 2.22 0.91 0.00 -0.66 -1.16 -1.55 -1.85 -2.10 -2.29 -2.46 -2.60 -2.71 -2.81 3.95 7.47 4.24 2.25 0.92 0.00 -0.67 -1.18 -1.57 -1.88 -2.12 -2.33 -2.49 -2.63 -2.75 -2.85 4.00 7.57 4.29 2.28 0.94 0.00 -0.68 -1.20 -1.59 -1.90 -2.15 -2.36 -2.53 -2.67 -2.79 -2.89 4.05 7.67 4.35 2.31 0.95 0.00 -0.69 -1.21 -1.61 -1.93 -2.18 -2.39 -2.56 -2.70 -2.82 -2.93 4.10 7.77 4.41 2.34 0.96 0.00 -0.70 -1.23 -1.63 -1.95 -2.21 -2.42 -2.59 -2.74 -2.86 -2.96 4.15 7.87 4.47 2.37 0.97 0.00 -0.71 -1.24 -1.65 -1.98 -2.24 -2.45 -2.63 -2.77 -2.90 -3.00 4.20 7.97 4.52 2.40 0.99 0.00 -0.72 -1.26 -1.68 -2.00 -2.27 -2.48 -2.66 -2.81 -2.93 -3.04 4.25 8.07 4.58 2.43 1.00 0.00 -0.73 -1.28 -1.70 -2.03 -2.30 -2.51 -2.69 -2.84 -2.97 -3.08 4.30 8.17 4.64 2.46 1.01 0.00 -0.74 -1.29 -1.72 -2.06 -2.33 -2.55 -2.73 -2.88 -3.01 -3.12 4.35 8.27 4.69 2.49 1.02 0.00 -0.75 -1.31 -1.74 -2.08 -2.35 -2.58 -2.76 -2.91 -3.04 -3.16 4.40 8.37 4.75 2.52 1.04 0.00 -0.76 -1.32 -1.76 -2.11 -2.38 -2.61 -2.79 -2.95 -3.08 -3.19 4.45 8.47 4.81 2.55 1.05 0.00 -0.76 -1.34 -1.78 -2.13 -2.41 -2.64 -2.83 -2.99 -3.12 -3.23 4.50 8.57 4.86 2.58 1.06 0.00 -0.77 -1.35 -1.80 -2.16 -2.44 -2.67 -2.86 -3.02 -3.16 -3.27 4.55 8.68 4.92 2.61 1.07 0.00 -0.78 -1.37 -1.82 -2.18 -2.47 -2.70 -2.90 -3.06 -3.19 -3.31 4.60 8.78 4.98 2.64 1.09 0.00 -0.79 -1.39 -1.84 -2.21 -2.50 -2.73 -2.93 -3.09 -3.23 -3.35 4.65 8.88 5.04 2.67 1.10 0.00 -0.80 -1.40 -1.87 -2.23 -2.53 -2.76 -2.96 -3.13 -3.27 -3.38 4.70 8.98 5.09 2.70 1.11 0.00 -0.81 -1.42 -1.89 -2.26 -2.55 -2.80 -3.00 -3.16 -3.30 -3.42 4.75 9.08 5.15 2.73 1.12 0.00 -0.82 -1.43 -1.91 -2.28 -2.58 -2.83 -3.03 -3.20 -3.34 -3.46 4.80 9.18 5.21 2.76 1.14 0.00 -0.83 -1.45 -1.93 -2.31 -2.61 -2.86 -3.06 -3.23 -3.38 -3.50 4.85 9.28 5.26 2.79 1.15 0.00 -0.84 -1.46 -1.95 -2.33 -2.64 -2.89 -3.10 -3.27 -3.41 -3.54 4.90 9.37 5.32 2.82 1.16 0.00 -0.85 -1.48 -1.97 -2.36 -2.67 -2.92 -3.13 -3.30 -3.45 -3.58