Figure 4. Panel a (top) shows the R_c-band folded light curve of GRO J0422+32 in quiescence (1994 November to 1995 February). The phase is computed for a period of P = 0.212140 d and an epoch for = 0.0 of T₀ = HJD 2449661.422, which corresponds to an inferior conjunction of the M star. Panel b (bottom) shows the data for the check star folded using the same ephemeris. Individual data points are shown as dots while the crosses are the result of averaging the curve into ten bins. Vertical bars represent the errors on the bin means.