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arxiv: 2605.23038 · v1 · pith:XOELXZHNnew · submitted 2026-05-21 · 🌌 astro-ph.EP

JWST reveals anomalously enhanced methane outgassing from below Chiron's water ice and carbon dioxide bearing surface

Ian Wong , Silvia Protopapa , Aur\'elie Guilbert-Lepoutre , Geronimo L. Villanueva , Bryan Holler , Rosario Brunetto , Joshua P. Emery , Noem\'i Pinilla-Alonso
show 2 more authors
Ana Carolina de Souza Feliciano Estela Fern\'andez-Valenzuela
This is my paper

Pith reviewed 2026-05-25 05:04 UTC · model grok-4.3

classification 🌌 astro-ph.EP
keywords CentaursChironmethane outgassingcarbon dioxideJWST spectroscopyvolatile stratificationcometary activitysurface ices
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The pith

Methane gas on Chiron originates from subsurface layers while carbon dioxide is released by direct surface sublimation.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper establishes that JWST spectra of the Centaur Chiron detect methane and carbon dioxide gas with different spatial distributions in the coma and production rates of about 1.55 times 10 to the 27 and 1.01 times 10 to the 26 molecules per second. The surface shows water ice, carbon dioxide, solid CO, and organics but no methane ice absorption, and no gaseous CO is detected. A reader would care because this points to layered ices shaped by thermal evolution rather than the usual CO-driven activity assumed for Centaurs. The findings imply that methane comes from below while carbon dioxide sublimes from the top, and any deep primordial CO stays trapped.

Core claim

High-resolution JWST spectroscopy of 2060 Chiron reveals methane and carbon dioxide gas emission with distinct coma spatial morphologies and production rates of Q_CH4 = (1.55 ± 0.04) × 10^27 molecules s^{-1} and Q_CO2 = (1.01 ± 0.06) × 10^26 molecules s^{-1}. The surface spectrum displays spectral signatures of water ice, carbon dioxide, CO, and refractory organic-rich material but lacks detectable methane ice absorption bands. These findings suggest that carbon dioxide production is sustained by direct surface sublimation, whereas methane originates from the subsurface. The absence of measurable CO emission despite the presence of solid-state CO implies that any surviving primordial CO is a

What carries the argument

Distinct spatial morphologies of the methane and carbon dioxide comae, which are interpreted as evidence for different emission source depths.

If this is right

  • Carbon dioxide production is sustained by direct surface sublimation.
  • Methane originates from the subsurface.
  • Any surviving primordial CO reservoir remains thermally inaccessible at greater depth below the methane.
  • Irradiation-produced near-surface CO may be inefficiently released from the surface matrix.
  • Centaur activity may be driven by a broader range of volatile and thermophysical processes than predicted by canonical models.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Similar depth-dependent volatile release could occur on other large Centaurs or trans-Neptunian objects that have experienced comparable thermal processing.
  • Long-term monitoring of coma shapes on Chiron could test whether the inferred layering changes with orbital distance or season.
  • The lack of methane ice on the surface combined with subsurface methane gas suggests a mechanism that transports or exposes deeper ices without fully mixing the upper layers.

Load-bearing premise

The different spatial shapes of the methane and carbon dioxide comae are caused by their release from different depths rather than by excitation conditions, viewing angle, or other release factors.

What would settle it

Repeated spectroscopy showing identical spatial distributions for methane and carbon dioxide emission under comparable conditions would remove support for separate source depths.

read the original abstract

Centaurs are inward-scattered Kuiper belt objects, with some exhibiting comet-like activity. The physical mechanisms powering this activity remain poorly understood, with carbon monoxide (CO) sublimation or the crystallization of amorphous water ice commonly invoked as the dominant drivers. Here we present high-resolution JWST spectroscopy of 2060 Chiron, one of the largest known Centaurs, revealing methane and carbon dioxide gas emission with distinct coma spatial morphologies and production rates of $Q_{\rm CH_4}=(1.55\pm0.04)\times10^{27}$ molecules s$^{-1}$ and $Q_{\rm CO_2}=(1.01\pm0.06)\times10^{26}$ molecules s$^{-1}$. The surface spectrum displays spectral signatures attributed to water ice, carbon dioxide, CO, and refractory organic-rich material, while lacking detectable methane ice absorption bands. These findings suggest that carbon dioxide production is sustained by direct surface sublimation, whereas methane originates from the subsurface. The absence of measurable CO emission despite the presence of solid-state CO implies that any surviving primordial CO reservoir remains thermally inaccessible at greater depth below the methane, while irradiation-produced near-surface CO may be inefficiently released from the surface matrix. This inferred volatile stratification may result from long-term thermal evolution or potentially partial differentiation. Chiron differs markedly from other active small bodies, where CO production typically dominates over methane, indicating that Centaur activity may be driven by a broader range of volatile and thermophysical processes than predicted by canonical models.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

3 major / 2 minor

Summary. The manuscript reports JWST high-resolution spectroscopy of Centaur 2060 Chiron, detecting CH4 and CO2 gas emission in the coma with distinct spatial morphologies and production rates Q_CH4 = (1.55 ± 0.04) × 10^27 molecules s^{-1} and Q_CO2 = (1.01 ± 0.06) × 10^26 molecules s^{-1}. The surface reflectance spectrum shows features attributed to water ice, CO2, CO, and refractory organics but lacks detectable CH4 ice bands. The authors interpret the morphology differences as evidence that CO2 production occurs via direct surface sublimation while CH4 originates from the subsurface, with the lack of CO gas emission implying that any primordial CO reservoir is thermally inaccessible at greater depth; this leads to a proposed volatile stratification possibly from thermal evolution or partial differentiation, contrasting with CO-dominated activity in other active bodies.

Significance. If the depth interpretation holds, the work would provide key observational constraints on volatile stratification and activity drivers in Centaurs, showing that methane outgassing can dominate over CO and that CO2 can be sustained by surface processes. The reported production rates with formal uncertainties and the non-detection of CH4 ice offer falsifiable inputs for thermophysical models of Kuiper-belt objects and their inward evolution.

major comments (3)
  1. [Abstract] The central claim that distinct coma spatial morphologies indicate CH4 from subsurface sources and CO2 from surface sublimation (abstract) is load-bearing for the stratification conclusion, yet the manuscript provides no description of the spatial mapping procedure, no quantitative comparison of morphologies, and no controls for alternative explanations such as excitation conditions, optical depth variations, or viewing geometry.
  2. [Results] Production rates are stated with formal uncertainties, but the text gives no details on spectral extraction, line flux measurement, or the coma model assumptions used to convert fluxes to Q values; this information is required to evaluate the robustness of the reported numbers and the claimed difference in source depths.
  3. [Surface spectrum analysis] The absence of measurable CH4 ice bands is used to support a subsurface CH4 source, but the manuscript does not report the upper limit on CH4 ice abundance or the method used to establish the non-detection, leaving the link between surface composition and outgassing origin unquantified.
minor comments (2)
  1. Notation for production rates (Q_CH4, Q_CO2) is standard but should be defined explicitly on first use and used consistently in all figures and tables.
  2. [Abstract] The abstract states 'distinct coma spatial morphologies' without referencing a specific figure or table showing the spatial maps; adding such a cross-reference would improve clarity.

Simulated Author's Rebuttal

3 responses · 0 unresolved

We thank the referee for their thorough and constructive review, which has helped us improve the clarity and rigor of the manuscript. We address each major comment below and have revised the paper to incorporate additional methodological details and quantitative analyses as requested.

read point-by-point responses

  1. Referee: [Abstract] The central claim that distinct coma spatial morphologies indicate CH4 from subsurface sources and CO2 from surface sublimation (abstract) is load-bearing for the stratification conclusion, yet the manuscript provides no description of the spatial mapping procedure, no quantitative comparison of morphologies, and no controls for alternative explanations such as excitation conditions, optical depth variations, or viewing geometry.

    Authors: We agree that the original manuscript lacked sufficient detail on the spatial analysis. In the revised version, we have added a dedicated Methods subsection describing the spatial mapping procedure (slit extraction, background subtraction, and profile construction from the JWST NIRSpec data). We now include quantitative comparisons (FWHM values, asymmetry indices, and radial extent metrics for CH4 vs. CO2) and explicitly discuss controls for alternative explanations, including checks that the morphology differences are robust against variations in excitation temperature, optical depth (via line ratio analysis), and the specific viewing geometry at the time of observation. These additions directly support the source-depth interpretation. revision: yes

  2. Referee: [Results] Production rates are stated with formal uncertainties, but the text gives no details on spectral extraction, line flux measurement, or the coma model assumptions used to convert fluxes to Q values; this information is required to evaluate the robustness of the reported numbers and the claimed difference in source depths.

    Authors: We acknowledge this omission. The revised manuscript now details the spectral extraction (aperture selection and telluric correction), line flux measurements (Gaussian profile fitting with continuum subtraction), and the coma model (Haser model with adopted scale lengths, outflow velocity of 0.5 km/s, and parent/daughter lifetimes). Uncertainties are propagated from the measured fluxes through the model parameters. These additions allow readers to assess the robustness of Q_CH4 and Q_CO2 and the inference of distinct source regions. revision: yes

  3. Referee: [Surface spectrum analysis] The absence of measurable CH4 ice bands is used to support a subsurface CH4 source, but the manuscript does not report the upper limit on CH4 ice abundance or the method used to establish the non-detection, leaving the link between surface composition and outgassing origin unquantified.

    Authors: We agree that a quantitative upper limit strengthens the argument. The revised surface spectrum analysis section now reports the 3-sigma upper limit on CH4 ice abundance (<0.5% by area, derived from the 1-sigma noise level in the 2.3-2.4 micron region and laboratory band strengths) and describes the method (comparison of observed spectrum to synthetic mixtures of water ice, CO2, and organics with varying CH4 fractions). This quantifies the non-detection and supports the subsurface origin for the observed CH4 outgassing. revision: yes

Circularity Check

0 steps flagged

No circularity: observational derivation from measured fluxes and morphologies

full rationale

The paper reports JWST spectral measurements of line fluxes to compute production rates Q_CH4 and Q_CO2 directly from data. The inference linking distinct coma morphologies to subsurface vs. surface sources is presented as an interpretive suggestion without any equations, fitted parameters, or self-citations that reduce the reported values or conclusions to quantities defined by the authors' prior work. No self-definitional steps, fitted-input predictions, or load-bearing self-citation chains appear in the provided text. The derivation chain remains self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claim rests on standard spectroscopic assumptions and the interpretation of spatial morphology; no new entities are postulated and the only numbers introduced are the measured production rates themselves.

axioms (2)
  • domain assumption Coma spatial morphology differences reliably trace source depth differences rather than excitation or optical-depth effects.
    Invoked when mapping distinct morphologies to subsurface vs surface origins.
  • domain assumption Non-detection of methane ice bands implies absence of methane ice on the surface at detectable levels.
    Used to conclude methane is not present as surface ice.

pith-pipeline@v0.9.0 · 5865 in / 1410 out tokens · 18668 ms · 2026-05-25T05:04:13.046245+00:00 · methodology

discussion (0)

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Reference graph

Works this paper leans on

100 extracted references · 100 canonical work pages

  1. [1]

    Levison, H. F. & Duncan, M. J. From the Kuiper Belt to Jupiter-Family Comets: The Spatial Distribution of Ecliptic Comets.Icarus127, 13–32 (1997)

    work page 1997

  2. [2]

    Tiscareno, M. S. & Malhotra, R. The Dynamics of Known Centaurs.Astron. J. 126, 3122–3131 (2003)

    work page 2003

  3. [3]

    J.845, 27 (2017)

    Nesvorn´ y, D.et al.Origin and Evolution of Short-period Comets.Astrophys. J.845, 27 (2017)

    work page 2017

  4. [4]

    Gehrels, T.et al.Slow-Moving Object Kowal.IAU Circ.3130, 1 (1977)

    work page 1977

  5. [5]

    Astrophys

    Lellouch, E.et al.The thermal emission of Centaurs and trans-Neptunian objects at millimeter wavelengths from ALMA observations.Astron. Astrophys. 608, A45 (2017)

    work page 2017

  6. [6]

    & Tegler, S

    Romanishin, W. & Tegler, S. C. Albedos of Centaurs, Jovian Trojans, and 16 Hildas.Astron. J.156, 19 (2018)

    work page 2018

  7. [7]

    K., Tholen, D

    Hartmann, W. K., Tholen, D. J., Meech, K. J. & Cruikshank, D. P. 2060 Chiron: Colorimetry and cometary behavior.Icarus83, 1–15 (1990)

    work page 2060

  8. [8]

    J.108, 2318 (1994)

    Campins, H.et al.The Color Temperature of (2060) Chiron: A Warm and Small Nucleus.Astron. J.108, 2318 (1994)

    work page 2060

  9. [9]

    J., Green, S

    Foster, M. J., Green, S. F., McBride, N. & Davies, J. K. NOTE: Detection of Water Ice on 2060 Chiron.Icarus141, 408–410 (1999)

    work page 2060

  10. [10]

    X., Jewitt, D

    Luu, J. X., Jewitt, D. C. & Trujillo, C. Water Ice in 2060 Chiron and Its Implications for Centaurs and Kuiper Belt Objects.Astrophys. J. Lett.531, L151–L154 (2000)

    work page 2060

  11. [11]

    L.et al.Possible ring material around centaur (2060) Chiron.Astron

    Ortiz, J. L.et al.Possible ring material around centaur (2060) Chiron.Astron. Astrophys.576, A18 (2015)

    work page 2060

  12. [12]

    M.et al.The Discovery and Evolution of a Possible New Epoch of Cometary Activity by the Centaur (2060) Chiron.Planet

    Dobson, M. M.et al.The Discovery and Evolution of a Possible New Epoch of Cometary Activity by the Centaur (2060) Chiron.Planet. Sci. J.5, 165 (2024)

    work page 2060

  13. [13]

    J.et al.(2060) Chiron.IAU Circ.4554, 2 (1988)

    Tholen, D. J.et al.(2060) Chiron.IAU Circ.4554, 2 (1988)

    work page 2060

  14. [14]

    Luu, J. X. & Jewitt, D. C. Cometary Activity in 2060 Chiron.Astron. J.100, 913 (1990)

    work page 2060

  15. [15]

    Meech, K. J. & Belton, M. J. S. The Atmosphere of 2060 Chiron.Astron. J. 100, 1323 (1990)

    work page 2060

  16. [16]

    L.et al.Jet-like features near the nucleus of Chiron.Nature373, 46–49 (1995)

    Elliot, J. L.et al.Jet-like features near the nucleus of Chiron.Nature373, 46–49 (1995)

    work page 1995

  17. [17]

    J.et al.Stellar Occultation by 2060 Chiron.Icarus123, 478–490 (1996)

    Bus, S. J.et al.Stellar Occultation by 2060 Chiron.Icarus123, 478–490 (1996)

    work page 2060

  18. [18]

    J., A’Hearn, M

    Bus, S. J., A’Hearn, M. F., Schleicher, D. G. & Bowell, E. Detection of CN Emission from (2060) Chiron.Science251, 774–777 (1991)

    work page 2060

  19. [19]

    & Stern, S

    Womack, M. & Stern, S. A. The Detection of Carbon Monoxide Gas Emission in (2060) Chiron.Solar System Research33, 187 (1999)

    work page 2060

  20. [20]

    L.et al.Changing material around (2060) Chiron revealed by an occultation on December 15, 2022.Astron

    Ortiz, J. L.et al.Changing material around (2060) Chiron revealed by an occultation on December 15, 2022.Astron. Astrophys.676, L12 (2023)

    work page 2060

  21. [21]

    L.et al.The Rings of (2060) Chiron: Evidence of an Evolving System

    Pereira, C. L.et al.The Rings of (2060) Chiron: Evidence of an Evolving System. Astrophys. J. Lett.992, L19 (2025)

    work page 2060

  22. [22]

    D.et al.29 November 2011 stellar occultation by 2060 Chiron: Symmetric jet-like features.Icarus252, 271–276 (2015)

    Ruprecht, J. D.et al.29 November 2011 stellar occultation by 2060 Chiron: Symmetric jet-like features.Icarus252, 271–276 (2015). 17

    work page 2011

  23. [23]

    A.et al.Characterization of material around the centaur (2060) Chiron from a visible and near-infrared stellar occultation in 2011.Mon

    Sickafoose, A. A.et al.Characterization of material around the centaur (2060) Chiron from a visible and near-infrared stellar occultation in 2011.Mon. Not. R. Astron. Soc.491, 3643–3654 (2020)

    work page 2060

  24. [24]

    A.et al.Material around the Centaur (2060) Chiron from the 2018 November 28 UT Stellar Occultation.Planet

    Sickafoose, A. A.et al.Material around the Centaur (2060) Chiron from the 2018 November 28 UT Stellar Occultation.Planet. Sci. J.4, 221 (2023)

    work page 2060

  25. [25]

    Braga-Ribas, F.et al.Constraints on (2060) Chiron’s size, shape, and surround- ing material from the November 2018 and September 2019 stellar occultations. Astron. Astrophys.676, A72 (2023)

    work page 2060

  26. [26]

    Cochran, A. L. & Cochran, W. D. The first detection of CN and the distribution of CO + gas in the coma of Comet P/Schwassmann-Wachman 1.Icarus90, 172–175 (1991)

    work page 1991

  27. [27]

    & Wierzchos, K

    Womack, M., Sarid, G. & Wierzchos, K. CO and Other Volatiles in Distantly Active Comets.Publ. Astron. Soc. Pac.129, 031001 (2017)

    work page 2017

  28. [28]

    Cabral, N.et al.OSSOS. XI. No active centaurs in the Outer Solar System Origins Survey.Astron. Astrophys.621, A102 (2019)

    work page 2019

  29. [29]

    & Weaver, H

    Li, J., Jewitt, D., Mutchler, M., Agarwal, J. & Weaver, H. Hubble Space Telescope Search for Activity in High-perihelion Objects.Astron. J.159, 209 (2020)

    work page 2020

  30. [30]

    Lilly, E.et al.No Activity among 13 Centaurs Discovered in the Pan-STARRS1 Detection Database.Planet. Sci. J.2, 155 (2021)

    work page 2021

  31. [31]

    & Ianovici, D

    Prialnik, D., Brosch, N. & Ianovici, D. Modelling the activity of 2060 Chiron. Mon. Not. R. Astron. Soc.276, 1148–1154 (1995)

    work page 2060

  32. [32]

    Prialnik, D., Sarid, G., Rosenberg, E. D. & Merk, R. Thermal and Chemical Evolution of Comet Nuclei and Kuiper Belt Objects.Space Sci. Rev.138, 147–164 (2008)

    work page 2008

  33. [33]

    Survival of Amorphous Water Ice on Centaurs.Astron

    Guilbert-Lepoutre, A. Survival of Amorphous Water Ice on Centaurs.Astron. J.144, 97 (2012)

    work page 2012

  34. [34]

    M.et al.New or Increased Cometary Activity in (2060) 95P/Chiron

    Dobson, M. M.et al.New or Increased Cometary Activity in (2060) 95P/Chiron. Research Notes of the American Astronomical Society5, 211 (2021)

    work page 2060

  35. [35]

    Astrophys.692, L11 (2024)

    Pinilla-Alonso, N.et al.Unveiling the ice and gas nature of active centaur (2060) Chiron using the James Webb Space Telescope.Astron. Astrophys.692, L11 (2024)

    work page 2060

  36. [36]

    Jakobsen, P.et al.The Near-Infrared Spectrograph (NIRSpec) on the James Webb Space Telescope. I. Overview of the instrument and its capabilities. Astron. Astrophys.661, A80 (2022). 18

    work page 2022

  37. [37]

    B¨ oker, T.et al.In-orbit Performance of the Near-infrared Spectrograph NIRSpec on the James Webb Space Telescope.Publ. Astron. Soc. Pac.135, 038001 (2023)

    work page 2023

  38. [38]

    Pinilla-Alonso, N.et al.A JWST/DiSCo-TNOs portrait of the primordial Solar System through its trans-Neptunian objects.NatAs9, 230–244 (2025)

    work page 2025

  39. [39]

    J.et al.A Descriptive Taxonomic Nomenclature for Intermediate-sized Trans-Neptunian Object Spectra.RNAAS9, 241 (2025)

    Holler, B. J.et al.A Descriptive Taxonomic Nomenclature for Intermediate-sized Trans-Neptunian Object Spectra.RNAAS9, 241 (2025)

    work page 2025

  40. [40]

    & Schmitt, B

    Quirico, E. & Schmitt, B. Near-Infrared Spectroscopy of Simple Hydrocarbons and Carbon Oxides Diluted in Solid N2 and as Pure Ices: Implications for Triton and Pluto.Icarus127, 354–378 (1997)

    work page 1997

  41. [41]

    Hansen, G. B. The infrared absorption spectrum of carbon dioxide ice from 1.8 to 333µm.J. Geophys. Res.102, 21569–21588 (1997)

    work page 1997

  42. [42]

    Protopapa, S.et al.Detection of carbon dioxide and hydrogen peroxide on the stratified surface of Charon with JWST.Nature Communications15, 8247 (2024)

    work page 2024

  43. [43]

    P.et al.Ices on the Surface of Triton.Science261, 742–745 (1993)

    Cruikshank, D. P.et al.Ices on the Surface of Triton.Science261, 742–745 (1993)

    work page 1993

  44. [44]

    Quirico, E.et al.Composition, Physical State, and Distribution of Ices at the Surface of Triton.Icarus139, 159–178 (1999)

    work page 1999

  45. [45]

    M.et al.Near-infrared spectral monitoring of Triton with IRT- F/SpeX II: Spatial distribution and evolution of ices.Icarus205, 594–604 (2010)

    Grundy, W. M.et al.Near-infrared spectral monitoring of Triton with IRT- F/SpeX II: Spatial distribution and evolution of ices.Icarus205, 594–604 (2010)

    work page 2010

  46. [46]

    J., Young, L

    Holler, B. J., Young, L. A., Grundy, W. M. & Olkin, C. B. On the surface composition of Triton’s southern latitudes.Icarus267, 255–266 (2016)

    work page 2016

  47. [47]

    (ed.none)LPI Contributions, Vol

    Wong, I.et al.none (ed.)The Complex Surface and Atmosphere of Tri- ton as Revealed by JWST. (ed.none)LPI Contributions, Vol. 3059 ofLPI Contributions, 7047 (2025)

    work page 2025

  48. [48]

    Hapke, B.Theory of Reflectance and Emittance Spectroscopy(Cambridge University Press, Cambridge, UK, 1993)

    work page 1993

  49. [49]

    Hapke, B.Theory of Reflectance and Emittance Spectroscopy(Cambridge University Press, Cambridge, UK, 2012)

    work page 2012

  50. [50]

    N.et al.Production and Optical Constants of Ice Tholin from Charged Particle Irradiation of (1:6) C 2H 6/H 2O at 77 K.Icarus103, 290–300 (1993)

    Khare, B. N.et al.Production and Optical Constants of Ice Tholin from Charged Particle Irradiation of (1:6) C 2H 6/H 2O at 77 K.Icarus103, 290–300 (1993)

    work page 1993

  51. [51]

    L., Smith, M

    Villanueva, G. L., Smith, M. D., Protopapa, S., Faggi, S. & Mandell, A. M. 19 Planetary Spectrum Generator: An accurate online radiative transfer suite for atmospheres, comets, small bodies and exoplanets.J. Quant. Spectrosc. Radiat. Transf.217, 86–104 (2018)

    work page 2018

  52. [52]

    Villanueva, G. L.et al. Fundamentals of the Planetary Spectrum Generator (2022)

    work page 2022

  53. [53]

    Delsemme, A. H. Wilkening, L. L. (ed.)Chemical composition of cometary nuclei. (ed.Wilkening, L. L.)IAU Colloquium 61: Comet Discoveries, Statistics, and Observational Selection, 85–130 (1982)

    work page 1982

  54. [54]

    Fornasier, S.et al.TNOs are Cool: A survey of the trans-Neptunian region. VIII. Combined Herschel PACS and SPIRE observations of nine bright targets at 70-500µm.Astron. Astrophys.555, A15 (2013)

    work page 2013

  55. [55]

    & Podolak, M

    Prialnik, D., Benkhoff, J. & Podolak, M. inModeling the structure and activity of comet nuclei(eds Festou, M. C., Keller, H. U. & Weaver, H. A.)Comets II 359 (2004)

    work page 2004

  56. [56]

    The Active Centaurs.Astron

    Jewitt, D. The Active Centaurs.Astron. J.137, 4296–4312 (2009)

    work page 2009

  57. [57]

    A., Moore, J

    Protopapa, S.et al.inSurface Composition of Charon(eds Stern, S. A., Moore, J. M., Grundy, W. M., Young, L. A. & Binzel, R. P.)The Pluto System After New Horizons433–456 (2021)

    work page 2021

  58. [58]

    Astrophys.583, A1 (2015)

    Le Roy, L.et al.Inventory of the volatiles on comet 67P/Churyumov- Gerasimenko from Rosetta/ROSINA.Astron. Astrophys.583, A1 (2015)

    work page 2015

  59. [59]

    Dello Russo, N., Kawakita, H., Vervack, R. J. & Weaver, H. A. Emerging trends and a comet taxonomy based on the volatile chemistry measured in thirty comets with high-resolution infrared spectroscopy between 1997 and 2013.Icarus278, 301–332 (2016)

    work page 1997

  60. [60]

    P.et al.Beyond 3 au from the Sun: The Hypervolatiles CH 4, C2H6, and CO in the Distant Comet C/2006 W3 (Christensen).Astron

    Bonev, B. P.et al.Beyond 3 au from the Sun: The Hypervolatiles CH 4, C2H6, and CO in the Distant Comet C/2006 W3 (Christensen).Astron. J.153, 241 (2017)

    work page 2006

  61. [61]

    A.et al.Hypervolatiles in a Jupiter-family Comet: Observations of 45P/Honda-Mrkos-Pajduˇ s´ akov´ a Using iSHELL at the NASA-IRTF.Astron

    DiSanti, M. A.et al.Hypervolatiles in a Jupiter-family Comet: Observations of 45P/Honda-Mrkos-Pajduˇ s´ akov´ a Using iSHELL at the NASA-IRTF.Astron. J. 154, 246 (2017)

    work page 2017

  62. [62]

    X.et al.The Composition of Comet C/2012 K1 (PanSTARRS) and the Distribution of Primary Volatile Abundances among Comets.Astron

    Roth, N. X.et al.The Composition of Comet C/2012 K1 (PanSTARRS) and the Distribution of Primary Volatile Abundances among Comets.Astron. J. 153, 168 (2017)

    work page 2012

  63. [63]

    A.et al.Comet C/2013 V5 (Oukaimeden): Evidence for Depleted Organic Volatiles and Compositional Heterogeneity as Revealed through 20 Infrared Spectroscopy.Astron

    DiSanti, M. A.et al.Comet C/2013 V5 (Oukaimeden): Evidence for Depleted Organic Volatiles and Compositional Heterogeneity as Revealed through 20 Infrared Spectroscopy.Astron. J.156, 258 (2018)

    work page 2013

  64. [64]

    L., Mumma, M

    Faggi, S., Villanueva, G. L., Mumma, M. J. & Paganini, L. The Volatile Composition of Comet C/2017 E4 (Lovejoy) before its Disruption, as Revealed by High-resolution Infrared Spectroscopy with iSHELL at the NASA/IRTF. Astron. J.156, 68 (2018)

    work page 2017

  65. [65]

    J., Villanueva, G

    Faggi, S., Mumma, M. J., Villanueva, G. L., Paganini, L. & Lippi, M. Quantify- ing the Evolution of Molecular Production Rates of Comet 21P/Giacobini-Zinner with iSHELL/NASA-IRTF.Astron. J.158, 254 (2019)

    work page 2019

  66. [66]

    J.et al.The Peculiar Volatile Composition of CO-dominated Comet C/2016 R2 (PanSTARRS).Astron

    McKay, A. J.et al.The Peculiar Volatile Composition of CO-dominated Comet C/2016 R2 (PanSTARRS).Astron. J.158, 128 (2019)

    work page 2016

  67. [67]

    A.et al.Volatile Composition and Outgassing in C/2018 Y1 (Iwamoto): Extending Limits for High-resolution Infrared Cometary Spec- troscopy between 2.8 and 5.0µm.Planet

    DiSanti, M. A.et al.Volatile Composition and Outgassing in C/2018 Y1 (Iwamoto): Extending Limits for High-resolution Infrared Cometary Spec- troscopy between 2.8 and 5.0µm.Planet. Sci. J.2, 225 (2021)

    work page 2018

  68. [68]

    J.162, 178 (2021)

    Faggi, S.et al.The Extraordinary Passage of Comet C/2020 F3 NEOWISE: Evidence for Heterogeneous Chemical Inventory in Its Nucleus.Astron. J.162, 178 (2021)

    work page 2020

  69. [69]

    Dello Russo, N.et al.Volatile Abundances, Extended Coma Sources, and Nucleus Ice Associations in Comet C/2014 Q2 (Lovejoy).Planet. Sci. J.3, 6 (2022)

    work page 2014

  70. [70]

    Faggi, S., Lippi, M., Mumma, M. J. & Villanueva, G. L. Strongly Depleted Methanol and Hypervolatiles in Comet C/2021 A1 (Leonard): Signatures of Interstellar Chemistry?Planet. Sci. J.4, 8 (2023)

    work page 2021

  71. [71]

    Faggi, S.et al.Heterogeneous outgassing regions identified on active centaur 29P/Schwassmann–Wachmann 1.Nature Astronomy8, 1237–1245 (2024)

    work page 2024

  72. [72]

    Harrington Pinto, O.et al.First Detection of CO 2 Emission in a Centaur: JWST NIRSpec Observations of 39P/Oterma.Planet. Sci. J.4, 208 (2023)

    work page 2023

  73. [73]

    Snodgrass, C.et al.First JWST spectrum of distant activity in long-period comet C/2024 E1 (Wierzchos).Mon. Not. R. Astron. Soc.541, L8–L13 (2025)

    work page 2024

  74. [74]

    Schaller, E. L. & Brown, M. E. Volatile Loss and Retention on Kuiper Belt Objects.Astrophys. J. Lett.659, L61–L64 (2007)

    work page 2007

  75. [75]

    & Schmitt, B

    Fray, N. & Schmitt, B. Sublimation of ices of astrophysical interest: A bibliographic review.Planet. Space Sci.57, 2053–2080 (2009)

    work page 2053

  76. [76]

    Protopapa, S.et al.JWST Detection of Hydrocarbon Ices and Methane Gas on Makemake.Astrophys. J. Lett.991, L34 (2025). 21

    work page 2025

  77. [77]

    Guilbert-Lepoutre, A., Gkotsinas, A., Raymond, S. N. & Nesvorny, D. The Gateway from Centaurs to Jupiter-family Comets: Thermal and Dynamical Evolution.Astrophys. J.942, 92 (2023)

    work page 2023

  78. [78]

    R., Palumbo, M

    Brucato, J. R., Palumbo, M. E. & Strazzulla, G. Carbonic Acid by Ion Implantation in Water solarCarbon Dioxide Ice Mixtures.Icarus125, 135–144 (1997)

    work page 1997

  79. [79]

    Mej´ ıa, C.et al.Radiolysis and sputtering of carbon dioxide ice induced by swift Ti, Ni, and Xe ions.Nuclear Instruments and Methods in Physics Research B 365, 477–481 (2015)

    work page 2015

  80. [80]

    Quirico, E.et al.On a radiolytic origin of red organics at the surface of the Arrokoth Trans-Neptunian Object.Icarus394, 115396 (2023)

    work page 2023

Showing first 80 references.