Bulge formation through disc instability - I. Stellar discs T. Devergne, A. Cattaneo, F. Bournaud, I. Koutsouridou, A. Winter, P. Dimauro, G. A. Mamon, W. Vacher and M. Varin A&A, 644 (2020) A56 Published online: 01 December 2020 DOI: 10.1051/0004-6361/201936439