English

Recent Chemo-morphological Coma Evolution of Comet 67P/Churyumov-Gerasimenko

Earth and Planetary Astrophysics 2025-07-21 v1

Abstract

We present VLT/MUSE observations of comet 67P/Churyumov-Gerasimenko during its 2021 perihelion passage, from which we generated simultaneous maps of dust, [OI], C2_2, NH2_2, and CN comae across 12 pre- and post-perihelion epochs. These maps reveal the evolutionary and compositional trends of 67P's coma and further enrich the context and findings of ESA's Rosetta mission. Dust and gas species displayed distinct structures, where NH2_2 and CN signals were uniquely associated with known dust fans, raising the question of possible correlation to the dust and contributions of extended sources. Localised fitted NH2_2 scale lengths were 1.5-1.9×\times larger than those fitted for the rest of the coma, which is consistent with an extended source component for northern pre-perihelion emissions. In the southern hemisphere, CN was correlated with a prominent and sharp dust structure, potentially revealing an extended source origin via larger dust particles that preserve the CN parent species, as evidenced by higher spectral slopes in the region. Gas maps depicted two distinct evolutionary regimes: (1) evolving H2_2O ([OI]1^{1}D) and C2_2 emissions driven by nucleus sublimation and subsolar insolation, and (2) stable NH2_2 and CN emissions associated with seasonal dynamics and possible distributed sources. Dust spectral slope maps revealed spectral slope trends consistent with Rosetta findings, while green/red [OI] ratios generally indicate a coma dominated by H2_2O.

Keywords

Cite

@article{arxiv.2507.13979,
  title  = {Recent Chemo-morphological Coma Evolution of Comet 67P/Churyumov-Gerasimenko},
  author = {Brian P. Murphy and Cyrielle Opitom and Colin Snodgrass and Sophie E. Deam and Léa Ferellec and Matthew Knight and Bin Yang and Vincent Okoth},
  journal= {arXiv preprint arXiv:2507.13979},
  year   = {2025}
}

Comments

63 pages, 14 figures, accepted for publication in the Planetary and Space Science journal Special Issue: 10 years of ROSETTA

R2 v1 2026-07-01T04:07:55.088Z