Magnitude equation in right ascension for the visual micrometer observations made at 030 Arcetri (5147 observations, 1894–1919). Top graph: residuals versus time, uncorrected (μ = +1.94″, σ = 2.07″). Middle graph: residuals versus visual magnitude of the asteroid; the least-squares regression line is R = −6.92 + (0.77 ± 0.01)M_V. Bottom graph: residuals versus time after magnitude correction (μ = 0.00″,σ = 1.86″).