title: Coronagraphs adapted to atmosphere conditions.
abstract: In this paper we show new ways to improve the performance of ground-based coronagraphy. We introduce adaptive coronagraphic masks whose profile is a binary version of the instantaneous atmospherically degraded star image. We also propose the hyper-Gaussian profile masks obtained by averaging adaptive masks. In addition, adaptive Lyot stops and hyper-Gaussian Lyot stops are analyzed. Computer simulations show that all these masks outperform the circular hard-edged mask and that a proper mask and stop combination significantly reduces the angular separation at which a faint companion can be detected.
authors.affiliation: Departamento de Física Aplicada, Universidad de Cantabria, Avenida de los Castros s/n, 39005 Santander, Spain. vallep@unican.es
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Cagigas
authors.forename: Pedro J
authors.initials: PJ
authors.lastname: Valle
authors.forename: Manuel P
authors.initials: MP
authors.lastname: Cagigal