English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Spectrophotometric data of the young planetary nebula M 3-27, from 2004 to2021, are presented and discussed. We corroborate that the H I Balmer linespresent features indicating they are emitted by the central star, therefore HeI lines were used to correct line fluxes by effects of reddening. Importantvariability on the nebular emission lines between 1964 to 2021, probablyrelated to density changes in the nebula, is reported. Diagnostic diagrams toderive electron temperatures and densities have been constructed. The nebulashows a very large density contrast with an inner density of the order of10$^{7}$ cm$^{-3}$ and an outer density of about $10^3 - 10^4$ cm$^{-3}$. Withthese values of density, electron temperatures of $16,000 - 18,000$ K have beenfound from collisionally excited lines. Due to the central star emits in theH$^+$ lines, ionic abundances relative to He$^+$ were calculated fromcollisionally excited and recombination lines, and scaled to H$^+$ byconsidering that He$^+$/H$^+$ $=$ He/H$ = 0.11$. ADF(O$^{+2}$) values were alsodetermined. Total abundance values obtained indicate sub-solar abundances,similarly to what is found in other comparable objects like IC 4997.

The extremely young planetary nebula M 3-27: an analysis of its evolution, physical conditions and abundances