N. Clark (Univ. Western Ontario), E. Peeters (Univ. Western Ontario), J. Cami (Univ. Western Ontario), M. Matsuura (Cardiff Univ.), A.G.G.M. Tielens (Univ. Maryland), P. Kavanagh (Maynooth Univ.), M.J. Barlow (Univ. Coll. London), J. Kastner (Rochester Inst. Tech.), K.E. Kraemer (Boston College), H. Monteiro (Cardiff Univ., Univ. Itajuba) R. Sahai (JPL), G.C. Sloan (STScI, UNC Chapel Hill), N.C. Sterling (Univ. West Georgia), J.R. Walsh (ESO), L.B.F.M. Waters (Radboud Univ., SRON), N.J. Wright (Keele Univ.) I. Aleman (Lab. Nac. Astrof. Brazil), B. Balick (Univ. Washington) J. Bernard-Salas (ACRI-ST), C. Bhatt (Univ. Western Ontario), J. Blommaert (Vrije Univ.), H.L. Dinerstein (Univ. Texas Austin), N. Hirano (ASIAA), O. Jones (Roy. Obs. Edinburgh), F. Kemper (Barcelona), E. Lagadec (Univ. Cote d'Azur), P. Moraga Baez (Univ. Western Ontario), M. Torki (ICE, CSIC, Barcelona), P.A.M. van Hoof (Roy. Obs. Belgium), K Volk (STScI), R. Wesson (Cardiff Univ., Univ. Coll. London, A. Zijlstra (Univ. Manchester)
2026, MNRAS, in press
Full manuscript available from the arXiv (2610.30441).
Polycyclic aromatic hydrocarbons (PAHs) and carbonaceous dust have been observed in Oxygen-rich planetary nebulae (PNe), yet their formation and evolution in these environments is an open question. We aim to study the formation and evolution of the PAHs in the O-rich PN NGC 6302 (the Butterfly Nebula), by characterizing the PAH emission throughout this object. We obtained JWST MIRI IFU spectroscopic observations of NGC 6302 pointed at its central source. From these, we extract four template spectra that are representative of the variation in PAH emission throughout NGC 6302. We detect the major PAH features at 6.2, 7.7, 8.6, 11.2, and 12.7 µm, and several minor PAH features. The template spectra vary in terms of their PAH feature widths, peak wavelengths, and relative intensities. The 11.2 µm PAH feature is class B, typical for PNe. The 6-9 µm PAH features are class A, which is less common for PNe. We estimate the PAH charge to be 75% cations on average, based on the 7.7/11.2 PAH feature ratio. The relative strengths of the 11-15 µm PAH features indicate a range of PAH edge structures. To ensure consistency in our observations and explain variable PAH feature widths, we propose a variation in the size of the PAHs throughout NGC 6302, and suggest variation in the shielding of these PAHs. The PAHs range from large and non-compact, to small and compact. We find that NGC 6302 formed PAHs in-situ in the current PN phase, likely from small hydrocarbons formed by the photodissociation of CO.
Last modified 23 October, 2026. © Gregory C. Sloan and others.