Detection of CO$_2$ ice in the planetary nebula NGC 6302
Abstract
Using JWST/MIRI observations, we report the detection of CO ice in the dusty torus of the planetary nebula NGC 6302, an environment generally considered hostile to fragile molecular species and ices due to intense UV irradiation. This detection accompanies cold (20-50 K) gas-phase CO along the same sightlines. The ice absorption profile exhibits a double-peak profile, a characteristic of pure, crystalline CO ice. The CO gas-to-ice ratio is more than an order of magnitude higher than in young stellar objects, pointing to distinct ice formation or processing mechanisms in evolved stellar environments. This discovery demonstrates that the dusty torus provides sufficient shielding to harbour ice chemistry, and that ice-mediated surface reactions must be incorporated into chemical models of planetary nebulae.
Cite
@article{arxiv.2602.22366,
title = {Detection of CO$_2$ ice in the planetary nebula NGC 6302},
author = {Charmi Bhatt and Simon W. Cao and Jan Cami and Nicholas Clark and Pascale Ehrenfreund and Els Peeters and Mikako Matsuura and G. C. Sloan and Harriet L. Dinerstein and Patrick Kavanagh and Kevin Volk and Isabel Aleman and Michael J. Barlow and Kay Justannont and Kathleen E. Kraemer and Joel H. Kastner and Francisca Kemper and Hektor Monteiro and Raghvendra Sahai and N. C. Sterling and Jeremy R. Walsh and L. B. F. M. Waters and Albert Zijlstra},
journal= {arXiv preprint arXiv:2602.22366},
year = {2026}
}