An example of the differential chromatic refraction correction applied for one night of observations with the 0.6 m Bollen & Chivens OPD telescope on April 18, 2007 – in right ascension (top) and declination (bottom). Gray dots represent the position offsets with regard to the ephemeris before the correction and black triangles after. The dashed line is the linear fit to the data without the refraction correction, and the full line is the linear fit to the corrected data. On this plot, △ B = 0.083.