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

NGC 6402 is among the most massive globular clusters in the Galaxy, butlittle is known about its detailed chemical composition. Therefore, we obtainedradial velocities and/or chemical abundances of 11 elements for 41 red giantbranch cluster members using high resolution spectra obtained with theMagellan-M2FS instrument. We find NGC 6402 to be only moderately metal-poorwith $\langle$[Fe/H]$\rangle$ = $-$1.13 dex ($\sigma$ = 0.05 dex) and to have amean heliocentric radial velocity of $-$61.1 km s$^{\rm -1}$ ($\sigma$ = 8.5 kms$^{\rm -1}$). In general, NGC 6402 exhibits mean composition properties thatare similar to other inner Galaxy clusters, such as [$\alpha$/Fe] $\sim$ $+$0.3dex, [Cr,Ni/Fe] $\sim$ 0.0 dex, and $\langle$[La/Eu]$\rangle$ = $-$0.08 dex.Similarly, we find large star-to-star abundance variations for O, Na, Mg, Al,and Si that are indicative of gas that experienced high temperatureproton-capture burning. Interestingly, we detect three distinct populations,but also find large gaps in the [O/Fe], [Na/Fe], and [Al/Fe] distributions thatmay provide the first direct evidence of delayed formation for intermediatecomposition stars. A qualitative enrichment model is discussed where clustersform stars through an early ($<$ 5$-$10 Myr) phase, which results in firstgeneration and "extreme" composition stars, and a delayed phase ($>$ 40 Myr),which results in the dilution of processed and pristine gas and the formationof intermediate composition stars. For NGC 6402, the missing intermediatecomposition stars suggest the delayed phase terminated prematurely, and as aresult the cluster may uniquely preserve details of the chemical enrichmentprocess.

Light Element Discontinuities Suggest an Early Termination of Star Formation in the Globular Cluster NGC 6402 (M14)