title: Active optics system of the VLT Survey Telescope.
abstract: This paper describes the active optics system of the VLT Survey Telescope, the 2.6-m survey telescope designed for visible wavelengths of the European Southern Observatory at Cerro Paranal, in the Atacama desert. The telescope is characterized by a wide field of view (1.42 deg diameter), leading to tighter active optics than in conventional telescopes, in particular for the alignment requirements. We discuss the effects of typical error sources on the image quality and present the specific solutions adopted for wavefront sensing and correction of the aberrations, which are based on the shaping of a monolithic primary mirror and the positioning of the secondary in five degrees of freedom.
authors.forename: Pietro
authors.initials: P
authors.lastname: Schipani
authors.forename: Lothar
authors.initials: L
authors.lastname: Noethe
authors.forename: Demetrio
authors.initials: D
authors.lastname: Magrin
authors.forename: Konrad
authors.initials: K
authors.lastname: Kuijken
authors.forename: Carmelo
authors.initials: C
authors.lastname: Arcidiacono
authors.forename: Javier
authors.initials: J
authors.lastname: Argomedo
authors.forename: Massimo
authors.initials: M
authors.lastname: Capaccioli
authors.forename: Massimo
authors.initials: M
authors.lastname: Dall'Ora
authors.forename: Sergio
authors.initials: S
authors.lastname: D'Orsi
authors.forename: Jacopo
authors.initials: J
authors.lastname: Farinato
authors.forename: Davide
authors.initials: D
authors.lastname: Fierro
authors.forename: Ronald
authors.initials: R
authors.lastname: Holzlöhner
authors.forename: Laurent
authors.initials: L
authors.lastname: Marty
authors.forename: Cesare
authors.initials: C
authors.lastname: Molfese
authors.forename: Francesco
authors.initials: F
authors.lastname: Perrotta
authors.forename: Roberto
authors.initials: R
authors.lastname: Ragazzoni
authors.forename: Salvatore
authors.initials: S
authors.lastname: Savarese
authors.forename: Andrew
authors.initials: A
authors.lastname: Rakich
authors.forename: Gabriele
authors.initials: G
authors.lastname: Umbriaco