Right: wide-field unresolved image of Jupiter and its vicinity (zoom in a region of ~1.2° × 1.2°) before source subtraction. The 3 bright nearby radio sources have the following flux density S at 73.8 MHz and spectral index α (following the convention S_ν ∝ ν^α): S = 2.24 ± 0.23 Jy and α = −1.0 for MRC 0204+110; S = 1.00 ± 0.12 Jy and α = −0.9 for NVSS J020530+112338; S = 1.94 ± 0.17 Jy and α = −0.9 for MRC 0202+114 (see NED database ned.ipac.caltech.edu). Left: measured spectra of these 3 radio sources at 12 frequencies between 127 and 172 MHz (solid color lines) compared with NED predictions (dash-dot color lines). The black lines show the total integrated flux density measured on the unresolved image of Jupiter before and after DD subtraction of surrounding radio sources at the same 12 frequencies. The difference between the two black lines is marginal.