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

In the solar neighbourhood, there are moving groups of stars with similarages and others of stars with heterogeneous ages as the field stars. To explainthese facts, we have constructed a simple model of three phases. Phase A: agiant interstellar cloud is uniformly accelerated (or decelerated) with respectto the field stars during a relatively short period of time (10 Myr) and thecloud's mass is uniformly increased; phase B: the acceleration (ordeceleration) and mass accretion of the cloud cease. The star formation spreadsthroughout the cloud, giving origin to stellar groups of similar ages; andphase C: the cloud loses all its gaseous component at a constant rate and inparallel is uniformly decelerated (or accelerated) until reaching the initialvelocity of phase A (case 1) or the velocity of the gas cloud remains constant(case 2). Both cases give equivalent results. The system equations for the starmotions governed by a time-dependent gravitational potential of the giant cloudand referred to a coordinate system co-moving with the cloud have been solvedanalytically. We have assumed a homogeneous spheroidal cloud of fixedsemi-major axis a=300 pc and of an initial density of 7 at cm^{-3}, with adensity increment of 100 per cent and a cloud's velocity variation of 30 kms^{-1}, from the beginning to the end of Phase A. The result is that about 4per cent of the field stars that are passing within the volume of the cloud atthe beginning of phase A is captured. The Sun itself could have been capturedby the same cloud that originated the moving groups of the solar neighbourhood.

Capture of field stars by giant interstellar clouds: the formation of moving stellar groups