Best-fit values of effective temperature, radius, and extinction obtained from the fit of the photometric SED of J17407 (see Table 3) with an absorbed blackbody model, with two different methods. Method one: best-fit values of T and R from the fit of the photometric SED, assuming distances in the range 1–30 kpc and for three values of A_v (see main text for more details). These solutions show up as three horizontal lines whose colours reflect the values assumed for A_v (see vertical colour bar on the right). A grid of distances (in units of kpc) in black is overplotted. Method two: “Γ-shape” coloured area shows the best-fit parameters ( < 2) T and R for different values of d, where the dependency of A_v on the distance is based on Green et al. (2019). For this method, the distances (in units of kpc) from 1.6 to 9.4 kpc are overplotted in red. The most relevant spectral classes for our analysis are shown in solid (main sequence), dashed (sub-giant), and dot-dashed (giant) red lines. The inset figure shows an example of a best-fitting SED (dashed red line). Blue points are the photometric measurements (see Table 3). The fit residuals (observed-model)/error are shown in the lower panel.