Loss timescales for electrons in the putative superbubble surrounding Cygnus OB2. The photon field from stars in Cygnus OB2 is evaluated at 20 pc. Diffuse dust and starlight are taken from the model by Popescu et al. (2017) and enhanced by a factor of two. Coulomb losses are shown for a hot, low-density, ionised medium (T = 10⁶ K, n_SB = 0.05 cm⁻³) following Schlickeiser 2002 (Sect. 4.5). All other timescales are computed with the GAMERA code (Hahn et al. 2022).