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 Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The globular cluster (GC) system of our Galaxy contains four planetarynebulae (PNe): K 648 (or Ps 1) in M15, IRAS 18333-2357 in M22, JaFu 1 in Pal 6,and JaFu 2 in NGC 6441. Because single-star evolution at the low stellar massof present-epoch GCs was considered incapable of producing visible PNe, theirorigin presented a puzzle. We imaged the PN JaFu 1 with the Hubble SpaceTelescope (HST) to obtain photometry of its central star (CS) andhigh-resolution morphological information. We imaged IRAS 18333-2357 withbetter depth and resolution, and we analyzed its archival HST spectra toconstrain its CS temperature and luminosity. All PNe in Galactic GCs now havehigh-quality HST data, allowing us to improve CS mass estimates. We findreasonably consistent masses between 0.53 and 0.58 Msun for all four objects,though estimates vary when adopting different stellar evolutionarycalculations. The CS mass of IRAS 18333-2357, though, depends strongly on itstemperature, which remains elusive due to reddening uncertainties. For all fourobjects, we consider their CS and nebular masses, their morphologies, and otherincongruities to assess the likelihood that these objects formed from binarystars. Although generally limited by uncertainties (~0.02 Msun) in post-AGBtracks and core mass vs. luminosity relations, the high-mass CS in K 648indicates a binary origin. The CS of JaFu 1 exhibits compact bright [O III] andHalpha emission, like EGB 6, suggesting a binary companion or disk. Evidence isweaker for a binary origin of JaFu 2.

Masses of the Planetary-Nebula Central Stars in the Galactic Globular-Cluster System from HST Imaging and Spectroscopy