Zusammenfassung
Balloon-borne astronomy is unique in that it allows for a level of image
stability, resolution, and optical backgrounds that are comparable to
space-borne systems due to greatly reduced atmospheric interference, but at a
fraction of the cost and over a significantly reduced development time-scale.
Instruments operating within visible-to-near-UV bands ($300$ - $900$ um) can
achieve a theoretical diffraction limited resolution of $0.01"$ from the
stratosphere ($35$ - $40$ km altitude) without the need for extensive adaptive
optical systems required by ground-based systems. The Superpressure
Balloon-borne Imaging Telescope ("SuperBIT") is a wide-field imager designed
to achieve 0.02$"$ stability over a 0.5$^\circ$ field-of-view, for deep single
exposures of up to 5 minutes. SuperBIT is thus well-suited for many
astronomical observations, from solar or extrasolar planetary observations, to
resolved stellar populations and distant galaxies (whether to study their
morphology, evolution, or gravitational lensing by foreground mass). We report
SuperBIT's design and implementation, emphasizing its two-stage real-time
stabilization: telescope stability to $1$ - $2"$ at the telescope level (a goal
surpassed during a test flight in September 2015) and image stability down to
$0.02"$ via an actuated tip-tilt mirror in the optical path (to be tested
during a flight in 2016). The project is progressing toward a fully
operational, three month flight from New Zealand by 2018
Nutzer