Mass-radius diagram for small well characterised planets (R < 2 R_⊕, ΔM < 30%) based on the TEPcat catalogue (Southworth 2011, visited on 14 April 2020). Planets orbiting stars with temperature T_eff < 4000 K are displayed in orange colour, while the rest is displayed as grey circles. GJ 3473 b is marked with a red diamond. For comparison, theoretical mass-radius relations from Zeng et al. (2016, 2019) are overlayed.