title: Designing asymmetric and branched petals for planet-finding occulters.
abstract: One of the proposed methods for finding small extrasolar planets is through use of an occulter, a spacecraft which flies in formation with a space-based telescope to block the light from a star, while leaving nearby planets unaffected. This is accomplished by placing the occulter far enough from the telescope to give it a small angular size, and by carefully choosing the shape to strongly suppress the starlight at the telescope aperture. For most designs, this shape takes the form of a number of bilaterally-symmetric structures called petals, arrayed about a circular central disk. In this paper, we show that the necessary number of petals may be reduced by the introduction of an asymmetry in the petal shape, and describe a a general procedure for producing such a shape by optimization for any occulter with petals. In addition, we show that permitting openings within each petal allows a number of additional modifications to be made without affecting the suppression.
authors.affiliation: Dept. of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544, USA. ecady@princeton.edu
authors.forename: Eric
authors.initials: E
authors.lastname: Cady
authors.forename: N J
authors.initials: NJ
authors.lastname: Kasdin
authors.forename: Stuart
authors.initials: S
authors.lastname: Shaklan
mesh_terms: D000465:Algorithms; D001256:Astronomy / Q000379:methods*; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008027:Light; D016083:Planets; D012031:Refractometry / Q000379:methods*; D012542:Scattering, Radiation