Abundances of the planetary nebula IC 4997

DOI

The planetary nebula (PN) IC 4997 is one of a few rapidly evolving objects with variable brightness and nebular emission around a hydrogen-deficient star. In this study, we have determined the physical conditions and chemical abundances of this object using the collisionally excited lines (CELs) and optical recombination lines (ORLs) measured from the medium-resolution spectra taken in 2014 July with the FIbre-fed Echelle Spectrograph on the Nordic Optical Telescope at La Palma Observatory. We derived electron densities of ~>3x10^4^cm^-3^ and electron temperatures of ~>14000K from CELs, whereas cooler temperatures of ~11000 and ~7000K were obtained from helium and heavy element ORLs, respectively. The elemental abundances deduced from CELs point to a metal-poor progenitor with [O/H]~8 and ADF(N2+)>~7. Further research is needed to find out how the ADFs and variable emissions are formed in this object and whether they are associated with a binary companion or a very late thermal pulse.

Identifier
DOI http://doi.org/10.26093/cds/vizier.75141217
Source https://dc.g-vo.org/rr/q/lp/custom/CDS.VizieR/J/MNRAS/514/1217
Related Identifier https://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/514/1217
Related Identifier http://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/514/1217
Metadata Access http://dc.g-vo.org/rr/q/pmh/pubreg.xml?verb=GetRecord&metadataPrefix=oai_b2find&identifier=ivo://CDS.VizieR/J/MNRAS/514/1217
Provenance
Creator Danehkar A.; Parthasarathy M.
Publisher CDS
Publication Year 2022
Rights https://cds.unistra.fr/vizier-org/licences_vizier.html
OpenAccess true
Contact CDS support team <cds-question(at)unistra.fr>
Representation
Resource Type Dataset; AstroObjects
Discipline Astrophysics and Astronomy; Interdisciplinary Astronomy; Interstellar medium; Natural Sciences; Observational Astronomy; Physics