High Angular Resolution Stellar Imaging with Occultations from the Cassini Spacecraft I: Observational Technique

TL;DR

This paper introduces a novel observational technique using the Cassini spacecraft to achieve high angular resolution stellar imaging through occultations, enabling detailed study of stellar atmospheres in the near-infrared.

Contribution

It demonstrates a new method for stellar imaging from the outer solar system using occultation events, expanding observational capabilities beyond Earth-based telescopes.

Findings

Successful measurement of Mira's angular diameter consistent with prior data

Validated the occultation technique for high-resolution stellar imaging

Recovered spatial information across 1-5 μm spectral range

Abstract

We present novel observations utilising the Cassini spacecraft to conduct an observing campaign for stellar astronomy from a vantage point in the outer solar system. By exploiting occultation events in which Mira passed behind the Saturnian ring plane as viewed by Cassini, parametric imaging data were recovered spanning the near-infrared. From this, spatial information at extremely high angular resolution was recovered enabling a study of the stellar atmospheric extension across a spectral bandpass spanning the 1 - 5 {\mu}m spectral region in the near-infrared. The resulting measurements of the angular diameter of Mira were found to be consistent with existing observations of its variation in size with wavelength. The present study illustrates the validity of the technique; more detailed exploration of the stellar physics obtained by this novel experiment will be the subject of forthcoming papers.