High-resolution imaging of comets and asteroids using bispectral techniques

Abstract

Abstract Speckle interferometry techniques have proven that very high angular resolution imaging could be performed from ground-based observatories, allowing the diffraction limit of optical telescopes to be reached. Yet, the full success of the technique heavily relies on the quality of the observing site since the overall S/N ratio varies as the fourth power of the atmospheric seeing. The Pic du Midi Observatory is renowned for the exceptional quality of its skies during a significant part of the year. A speckle imaging program was consequently designed at the 2 m Bernard Lyot telescope (TBL) to apply this method to a wide set of astrophysical problems that could benefit from a resolution of 0.06 in V . A speckle camera has been built and is currently being tested. We briefly present the image restoration methods we have developed and tested on both synthetic and real data. These methods are based on bispectral phase recovery with leastsquares minimization, followed by regularized deconvolution. We then describe the potential of the technique for the study of small bodies of the solar system.