HCN detection in the Kreutz sungrazing comet C/2026 A1 (MAPS) shortly before its disruption

Abstract

Context. Kreutz sungrazing comets are characterised by extremely small perihelion distances (q < 3.45 R). These objects are of particular interest because their intense activity and fragmentation can expose material from deeper within the nucleus, providing unique access to their bulk chemical composition rather than merely their surface layers. Aims. The discovery of C/2026 A1 (MAPS) three months before its perihelion offered a rare opportunity to investigate the composition and activity of a Kreutz sungrazing comet. We present the first millimetre wavelength study of this type of comet. Methods. We observed C/2026 A1 (MAPS) with the IRAM 30-m telescope from April 1 to April 3 2026 at heliocentric distances rh = 0.10-0.23 au, the three days preceding its perihelion and full disintegration. We analysed the molecular emissions using non-local thermodynamic equilibrium radiative transfer models to derive molecular production rates. Results. We report the first HCN detection in a Kreutz sungrazer through its (3-2) transition at 265.886 GHz, enabling us to characterise the variability of its activity. We witnessed two outbursts, on April 1 and April 3. The second one, occurring the day before the disintegration of C/2026 A1 (MAPS), led to the release of 0.4% to 1.2% of the total cometary mass, thus suggesting a pre-disruption before entering the Roche limit region. We also obtained upper limits for HNC, CS, H2CO, CO, OCS and CH3OH

Radio view of the Peanut cluster: merger-induced stripping and a radio halo shortly after pericentric passage
K. Rajpurohit, N. Lyskova, E. Churazov +25
arXiv26 Oct 2026PreprintarXiv licenceFull textCosmology GalaxiesarXiv
Rates of tidal disruption events from constrained cosmological simulations of the local Universe: population properties and implications for transient surveys
Julian S Sommer, Ildar Khabibullin, Klaus Dolag +4
HAL1 Sep 2026PreprintLicence not statedGeneral astronomy General physicsHAL
Tidal Disruption Events on FIRE: Illuminating the Cosmic Evolution of Tidal Disruption Rates
Rudrani Kar Chowdhury, Lixin Dai, Janet N.Y. Chang +1
The Astrophysical Journal2 Nov 2026Peer-reviewedCC BY 4.0Full textSolar & stellar physicsIOP/AASCrossref
Before fragmentation: From uniform clouds to stellar clusters
A. Giannetti, T.G.S. Pillai, J. Kauffmann +4
Astronomy & Astrophysics7 Oct 2026Peer-reviewedPublisher termsSolar & stellar physicsCrossref
TDEs on FIRE: Illuminating the Cosmic Evolution of Tidal Disruption Rates
Rudrani Kar Chowdhury, Lixin Dai, Janet N. Y. Chang +1
arXiv29 Oct 2026PreprintCC BY 4.0Full textHigh-energy astrophysicsarXiv

Cite

BibTeX RIS

BibTeX

@misc{palluet2026detection,
  title = {{HCN detection in the Kreutz sungrazing comet C/2026 A1 (MAPS) shortly before its disruption}},
  author = {Amélie Godard Palluet and Dominique Bockelée-Morvan and Nicolas Biver and Raphael Moreno and Martin Cordiner and David Haasler and Jacques Crovisier and Víctor M. Rivilla},
  howpublished = {arXiv},
  year = {2026},
  month = nov,
  doi = {10.48550/arxiv.2611.03417},
  eprint = {2611.03417},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2611.03417},
}

RIS

TY  - UNPB
TI  - HCN detection in the Kreutz sungrazing comet C/2026 A1 (MAPS) shortly before its disruption
AU  - Amélie Godard Palluet
AU  - Dominique Bockelée-Morvan
AU  - Nicolas Biver
AU  - Raphael Moreno
AU  - Martin Cordiner
AU  - David Haasler
AU  - Jacques Crovisier
AU  - Víctor M. Rivilla
PY  - 2026
DA  - 2026/11/02
PB  - arXiv
DO  - 10.48550/arxiv.2611.03417
UR  - https://arxiv.org/abs/2611.03417
AB  - Context. Kreutz sungrazing comets are characterised by extremely small perihelion distances (q < 3.45 R). These objects are of particular interest because their intense activity and fragmentation can expose material from deeper within the nucleus, providing unique access to their bulk chemical composition rather than merely their surface layers. Aims. The discovery of C/2026 A1 (MAPS) three months before its perihelion offered a rare opportunity to investigate the composition and activity of a Kreutz sungrazing comet. We present the first millimetre wavelength study of this type of comet. Methods. We observed C/2026 A1 (MAPS) with the IRAM 30-m telescope from April 1 to April 3 2026 at heliocentric distances rh = 0.10-0.23 au, the three days preceding its perihelion and full disintegration. We analysed the molecular emissions using non-local thermodynamic equilibrium radiative transfer models to derive molecular production rates. Results. We report the first HCN detection in a Kreutz sungrazer through its (3-2) transition at 265.886 GHz, enabling us to characterise the variability of its activity. We witnessed two outbursts, on April 1 and April 3. The second one, occurring the day before the disintegration of C/2026 A1 (MAPS), led to the release of 0.4% to 1.2% of the total cometary mass, thus suggesting a pre-disruption before entering the Roche limit region. We also obtained upper limits for HNC, CS, H2CO, CO, OCS and CH3OH
ER  -

Abstract

Related

Cite