The 1998 November 14 Occultation of GSC 0622-00345 by Saturn. I. Techniques for Ground-Based Stellar Occultations

TL;DR

This paper details advanced ground-based observational techniques for stellar occultations, demonstrating high-quality data acquisition during Saturn's 1998 occultation of GSC 0622-00345, with implications for planetary atmosphere studies.

Contribution

It introduces improved methods for aperture positioning, telluric scintillation removal, and timing in occultation observations, enhancing data quality and reliability.

Findings

Achieved a high signal-to-noise ratio of 267 per scale height.

Demonstrated techniques applicable to future occultation observations.

Provided detailed methodology for atmospheric and ring data analysis.

Abstract

On 1998 November 14, Saturn and its rings occulted the star GSC 0622-00345. We observed atmospheric immersion with NSFCAM at the National Aeronautics and Space Administration's Infrared Telescope Facility on Mauna Kea, Hawaii. Immersion occurred at 55.5\circ S planetocentric latitude. A 2.3 {\mu}m, methane-band filter suppressed reflected sunlight. Atmospheric emersion and ring data were not successfully obtained. We describe our observation, light-curve production, and timing techniques, including improvements in aperture positioning, removal of telluric scintillation effects, and timing. Many of these techniques are known within the occultation community, but have not been described in the reviewed literature. We present a light curve whose signal-to-noise ratio per scale height is 267, among the best ground-based signals yet achieved, despite a disadvantage of up to 8 mag in the stellar flux compared to prior work.