First observations and magnitude measurement of Starlink’s Darksat J. Tregloan-Reed, A. Otarola, E. Ortiz, V. Molina, J. Anais, R. González, J. P. Colque and E. Unda-Sanzana A&A, 637 (2020) L1 Published online: 30 April 2020 DOI: 10.1051/0004-6361/202037958