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

Preliminary results on the ongoing spectroscopic study of the six brightestOrion Trapezium stars is presented here. The main purpose of this work is tobetter understand the multiplicity and stability of each of these subsystemsand the dynamical future of the group. So far the most interesting resultsreached are: 1) The orbit of the secondary star of the eclipsing Component A(V1016 Ori) is highly inclined with respect to the equatorial plane of itsprimary star. 2) The also eclipsing binary BM Ori (Trapezium Component B) doeshave a tertiary member with period about 3.5 years, as proposed by Vitrichenko& Klochkova (2004), and is the same as the companion recently found by theGRAVITY collaboration et al. (2018}. 3) Component D is indeed a spectroscopicand interferometric double star with a relatively high-mass companion($q=M_2/M_1=0.5$) and period $52.90\pm0.05\,d$. 4) Component F, is a CP star(B7.5 p Si); its radial velocity, $23.2\pm4.2\,km\,s^{-1}$, is smaller thanthat of all other Trapezium members and, possibly, the evolutionary stage ofthe star is more advanced than that of members with similar mass. Consequently,Component F is probably not physically related to the Trapezium. Severalevidences point to the extreme youth of this stellar group; its further study,most likely, will shed light on the formation processes of massive stars.

Multiplicity of the Orion Trapezium stars