Gravitational-darkening of Altair from interferometryA. Domiciano de Souza, P. Kervella, S. Jankov, F. Vakili, N. Ohishi, T. E. Nordgren and L. AbeA&A, 442 2 (2005) 567-578DOI: https://doi.org/10.1051/0004-6361:20042476