The luminosity evolution of nova shells - I. A new analysis of old data C. Tappert, N. Vogt, A. Ederoclite, L. Schmidtobreick, M. Vučković and L. L. Becegato A&A, 641 (2020) A122 Published online: 18 September 2020 DOI: 10.1051/0004-6361/202037913