Skip to content
DraconiticResearch
Search Sources API
203,234 studies31 sourcesUpdated 55 min ago
Peer-reviewedCC BYThe Astrophysical Journal

Postperihelion Integral Field Spectroscopy of the Interstellar Comet 3I/ATLAS

  • W. B. Hoogendam1
  • D. O. Jones1
  • Bin Yang2,3
  • Benjamin J. Shappee1
  • James J. Wray4,1
  • Karen J. Meech1
  • Chris Ashall1
  • D. Desai1
  • Jason T. Hinkle5,1,6
  • Andrew Hoffman1
  • K. Medler1
  • Cameron Pfeffer1
1 more authors
  • Ruining Zhao7
7 affiliations
  1. 1University of Hawai'i
  2. 2Planetary Science Institute
  3. 3Universidad Diego Portales
  4. 4Georgia Institute of Technology
  5. 5NSF-Simons AI Institute for the Sky (SkAI)
  6. 6University of Illinois Urbana-Champaign
  7. 7Chinese Academy of Sciences
Open at sourceDOICite

Abstract

The environs of other stellar systems may be directly probed by analyzing the cometary activity of interstellar objects. The recently discovered interstellar object 3I/ATLAS was the subject of an intensive worldwide follow-up campaign in its preperihelion approach. Now, 3I/ATLAS has begun its postperihelion departure from the solar system. In this paper, we report the first postperihelion blue-sensitive integral-field unit spectroscopy of 3I/ATLAS using the Keck Cosmic Web Imager on 2025 November 16. We confirm previously reported CN, Fe, and Ni outgassing along with detections of carbon chain molecules C 2 and C 3 . We calculate production rates for each species. We find Fe and Ni production rates of Q Fe = (9.55 ± 3.96) × 10 25 atoms s −1 and Q Ni = (6.61 ± 2.74) × 10 25 atoms s −1 , resulting in a ratio of log ( Q Ni / Q Fe ) = − 0.16 ± 0.03 , which matches solar system comets well and continues the preperihelion trend of declining log ( Q Ni / Q Fe ) with r h . We investigate the radial distributions of these elemental species and find characteristic e -folding radii of 3880 ± 39 km for Ni, 6053 ± 68 km for CN, 4194 ± 45 km for C 2 , and 3833 ± 45 km for C 3 . Compared to preperihelion measurements, these radii have increased by a factor of ∼6.5–7. Our postperihelion observations reveal that 3I/ATLAS continues to exhibit cometary behavior broadly consistent with solar system comets.

Related

  1. Postperihelion Coma Composition of the Interstellar Comet 3I/ATLAS from Optical Spectroscopy
    Ruining Zhao, Xiliang Zhang, Bin Yang +4
    The Astrophysical Journal LettersPeer-reviewedCC BYFull text11 citedPlanetary science & exoplanetsOpenAlex
  2. Contemporaneous Optical and Near-infrared Observations of the Interstellar Comet 3I/ATLAS Pre- and Postperihelion
    K. Medler, W. B. Hoogendam, Chris Ashall +12
    The Astronomical JournalPeer-reviewedCC BY9 citedPlanetary science & exoplanetsOpenAlex
  3. High-resolution optical spectroscopy reveals the distinctive volatile composition of the interstellar comet 3I/ATLAS
    K. Aravind, E. Jehin, C. Opitom +9
    Astronomy & AstrophysicsPeer-reviewedPublisher termsPlanetary science & exoplanetsCrossref
  4. The Inbound Gas and Dust Evolution of Interstellar Comet 3I/ATLAS from Optical Spectroscopy and Multiband Photometry*
    T. Santana-Ros, Alexey V. Sergeyev, Oleksandra V. Ivanova +9
    The Astrophysical JournalPeer-reviewedCC BYFull text5 citedPlanetary science & exoplanetsOpenAlex
  5. High-resolution optical spectroscopy reveals the distinctive volatile composition of the interstellar comet 3I/ATLAS
    K. Aravind, E. Jehin, C. Opitom +9
    arXivPreprintarXiv licenceFull textPlanetary science & exoplanetsarXiv

Cite

BibTeXRIS
BibTeX
@article{hoogendam2026postperihelion,
  title = {{Postperihelion Integral Field Spectroscopy of the Interstellar Comet 3I/ATLAS}},
  author = {W. B. Hoogendam and D. O. Jones and Bin Yang and Benjamin J. Shappee and James J. Wray and Karen J. Meech and Chris Ashall and D. Desai and Jason T. Hinkle and Andrew Hoffman and K. Medler and Cameron Pfeffer and Ruining Zhao},
  journal = {The Astrophysical Journal},
  year = {2026},
  month = may,
  doi = {10.3847/1538-4357/ae6243},
  url = {https://doi.org/10.3847/1538-4357/ae6243},
  note = {CC BY},
}
RIS
TY  - JOUR
TI  - Postperihelion Integral Field Spectroscopy of the Interstellar Comet 3I/ATLAS
AU  - W. B. Hoogendam
AU  - D. O. Jones
AU  - Bin Yang
AU  - Benjamin J. Shappee
AU  - James J. Wray
AU  - Karen J. Meech
AU  - Chris Ashall
AU  - D. Desai
AU  - Jason T. Hinkle
AU  - Andrew Hoffman
AU  - K. Medler
AU  - Cameron Pfeffer
AU  - Ruining Zhao
PY  - 2026
DA  - 2026/05/28
JO  - The Astrophysical Journal
DO  - 10.3847/1538-4357/ae6243
UR  - https://doi.org/10.3847/1538-4357/ae6243
AB  - The environs of other stellar systems may be directly probed by analyzing the cometary activity of interstellar objects. The recently discovered interstellar object 3I/ATLAS was the subject of an intensive worldwide follow-up campaign in its preperihelion approach. Now, 3I/ATLAS has begun its postperihelion departure from the solar system. In this paper, we report the first postperihelion blue-sensitive integral-field unit spectroscopy of 3I/ATLAS using the Keck Cosmic Web Imager on 2025 November 16. We confirm previously reported CN, Fe, and Ni outgassing along with detections of carbon chain molecules C 2 and C 3 . We calculate production rates for each species. We find Fe and Ni production rates of Q Fe = (9.55 ± 3.96) × 10 25 atoms s −1 and Q Ni = (6.61 ± 2.74) × 10 25 atoms s −1 , resulting in a ratio of log ( Q Ni / Q Fe ) = − 0.16 ± 0.03 , which matches solar system comets well and continues the preperihelion trend of declining log ( Q Ni / Q Fe ) with r h . We investigate the radial distributions of these elemental species and find characteristic e -folding radii of 3880 ± 39 km for Ni, 6053 ± 68 km for CN, 4194 ± 45 km for C 2 , and 3833 ± 45 km for C 3 . Compared to preperihelion measurements, these radii have increased by a factor of ∼6.5–7. Our postperihelion observations reveal that 3I/ATLAS continues to exhibit cometary behavior broadly consistent with solar system comets.
SN  - 0004-637X
SN  - 1538-4357
ER  -