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 classical problem of the stability of stationary stellar spherical models with purely radial motion is reconsidered. The problem is due to strong central singularity in the density distribution, resulting in not entirely rigorous proof made in the well-known Antonov's paper. To avoid this difficulty, we construct a suitable two-parametric series of models with moderately elongated and nearly radial orbits, without singularity, and pass to the limiting case of models with orbits arbitrarily close to purely radial. The stability of the series with respect to odd and even spherical harmonics is considered. The growth rates of aperiodic even modes increase indefinitely when approaching purely radial models.

Instability of Stationary Spherical Models with Orbits Arbitrarily Close to Radial