Observational signatures of strongly naked singularities: image of the thin accretion disk Galin Gyulchev, Jutta Kunz, Petya Nedkova, Tsvetan Vetsov and Stoytcho Yazadjiev Eur. Phys. J. C, 80 11 (2020) 1017 Published online: 03 November 2020 DOI: 10.1140/epjc/s10052-020-08575-7