Left: J1407+0453 at 1400 MHz. The grey scale represents the flux density of the source. Right: J1407+0453 at 1400 MHz in a contour overlaid with the optical image taken from the 9th data release of the Dark Energy Spectroscopic Instrument’s Legacy Imaging Surveys (DESI LS DR9; Schlegel et al. 2021). For both images, the contour levels are at 3σ × (1, 1.4, 2, 2.8, 4, 5.7, 8, 10, 11, 12, 12.5, 13.2, 13.5, 13.8, 14, 14.2, 14.3, 15), where σ = 133 μJy beam⁻¹ is the mean rms noise around the FIRST map.