JWST Observations of the Ring Nebula (NGC 6720). III. A Dusty Disk around Its Central Star
Journal article, 2025
The planetary nebula NGC 6720, also known as the "Ring Nebula," is one of the most iconic examples of nearby planetary nebulae whose morphologies present a challenge to our theoretical understanding of the processes that govern the deaths of most stars in the Universe that evolve on a Hubble time. We present new imaging with JWST of the central star of this planetary nebula (CSPN) and its close vicinity, in the near-to-mid-IR wavelength range. We find the presence of a dust cloud around the CSPN, both from the spectral energy distribution at wavelengths greater than or similar to 5 mu m as well as from radially extended emission in the 7.7, 10, and 11.3 mu m images. From the modeling of these data, we infer that the CSPN has a luminosity of 310 L circle dot and is surrounded by a dust cloud with a size of similar to 2600 au, consisting of relatively small amorphous silicate dust grains (radius similar to 0.01 mu m) with a total mass of 1.9 x 10-6 M circle plus. However, our best-fit model shows a significant lack of extended emission at 7.7 mu m-we show that such emission can arise from a smaller (7.3 x 10-7 M circle plus) but uncertain mass of (stochastically heated) ionized polycyclic aromatic hydrocarbon (PAHs). However, the same energetic radiation also rapidly destroys PAH molecules, suggesting that these are most likely being continuously replenished, via the outgassing of cometary bodies and/or the collisional grinding of planetesimals. We also find significant photometric variability of the central source that could be due to the presence of a close dwarf companion of mass <= 0.1 M circle dot.
Author
Raghvendra Sahai
California Institute of Technology (Caltech)
Griet van de Steene
Royal Observatory of Belgium
Peter A. M. van Hoof
Royal Observatory of Belgium
Albert Zijlstra
University of Manchester
Kevin Volk
Space Telescope Science Institute (STScI)
Harriet L. Dinerstein
University of Texas
Michael J. Barlow
University College London (UCL)
Els Peeters
Western University
SETI Institute
Arturo Manchado
Instituto de Astrofísica de Canarias
Spanish National Research Council (CSIC)
University of La Laguna
Mikako Matsuura
Cardiff University
Jan Cami
Western University
SETI Institute
Nick L. J. Cox
CERGA (Centre d'Etudes et de Recherche de Grasse ACRI)
Innovative Common Laboratory For Space Spectroscopy (INCLASS)
Isabel Aleman
Laboratorio Nacional de Astrofisica, Itajuba
Jeronimo Bernard-Salas
Innovative Common Laboratory For Space Spectroscopy (INCLASS)
CERGA (Centre d'Etudes et de Recherche de Grasse ACRI)
Nicholas Clark
Western University
Kay Justtanont
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
Kyle F. Kaplan
University of Texas
Patrick J. Kavanagh
Maynooth University
Roger Wesson
University College London (UCL)
Cardiff University
Astrophysical Journal
0004-637X (ISSN) 1538-4357 (eISSN)
Vol. 985 1 101Subject Categories (SSIF 2025)
Astronomy, Astrophysics, and Cosmology
DOI
10.3847/1538-4357/adc91c
Related datasets
JWST images of the Ring Nebula (NGC 6720) [dataset]
DOI: https://doi.org/10.17909/bv01-qg73