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

We report the first detection of CO J = 3-2 around a truly metal-poor evolvedstar. RU Vulpeculae is modelled to have Teff ~ 3620 K, L ~ 3128 +/- 516 L_Sun,log(g) = 0.0 ~ 0.2 dex and [Fe/H] = -1.3 to -1.0 dex, and is modelled to haverecently undergone a thermal pulse. Its infrared flux has approximately doubledover 35 years. ALMA observations show the 3-2 line is narrow (half-width~1.8-3.5 km/s). The 2-1 line is much weaker: it is not confidently detected.Spectral-energy-distribution fitting indicates very little circumstellarabsorption, despite its substantial mid-infrared emission. A VISIR mid-infraredspectrum shows features typical of previously observed metal-poor stars,dominated by a substantial infrared excess but with weak silicate and(possibly) Al2O3 emission. A lack of resolved emission, combined with weak 2!1emission, indicates the dense circumstellar material is truncated at largeradii. We suggest that rapid dust condensation is occurring, but with anaspherical geometry (e.g., a disc or clumps) that does not obscure the star. Wecompare with T UMi, a similar star which is currently losing its dust.

Circumstellar CO J = 3-2 detected around the evolving metal-poor ([Fe/H] ~ -1.15 dex) AGB star RU Vulpeculae