Study of Pluto's Atmosphere Based on 2020 Stellar Occultation Light Curve Results

TL;DR

This study analyzes Pluto's atmosphere using stellar occultation data from 2020, estimating atmospheric pressure and observing seasonal volatile transport effects consistent with previous findings.

Contribution

It provides updated atmospheric pressure measurements and confirms ongoing seasonal N2 ice sublimation on Pluto based on 2020 occultation data.

Findings

Pluto's atmospheric pressure at 1215 km is 6.72 μbar.

The pressure trend continues to rise, aligning with seasonal models.

N2 ice in Sputnik Planitia is increasingly sublimating due to heating.

Abstract

On 6 Jun 2020, Pluto's stellar occultation was successfully observed at a ground-based observatory and Pluto's atmospheric parameters were investigated. We used an atmospheric model of Pluto (DO15), assuming a spherical and transparent pure N2 atmosphere. Using ray-tracing code the stellar occultation light curve was satisfactorily fitted to this model. We found that Pluto's atmospheric pressure at the reference radius of 1215 km is 6.72+_0.21 {\mu}bar. Our estimated pressure shows a continuation of the increasing pressure studied in 2016 consistent with a seasonal volatile transport model. We concluded that the N2 condensation processes in the Sputnik Planitia glacier are increasing due to the heating of the N2 ice in this basin. This study's result was shown on the diagram of the annual evolution of atmospheric pressure.