Spectral energy distribution of the host galaxy from 1000 to 60 000 Å (black dots). The solid line displays the best fitting model of the SED. The red squares represent the model-predicted magnitudes. The fitting parameters are shown in the upper left corner. The abbreviation ‘n.o.f.’ stands for the number of filters. We performed measurements on the entire host flux (upper panel), the faint tail (middle panel), and the star-forming blob (lower panel) where SN 2021adxl exploded. (a) Flux from the host, including the flux from the bright head and the ffuse tail. (b) Flux from diffuse tail to the southwest. (c) Flux from bright star-forming head to the northwest.