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

Stellar evolution in close binary systems is strongly influenced by masstransfer from one star to the other when one component fills its zero-velocitysurface or Roche Lobe. SS Lep is a fairly nearby close binary showing the Algolparadox and a shell spectrum, both indicative of (past) mass transfer. To studythe process of mass transfer and its evolutionary consequences, we aim at adirect characterisation of the spatial dimensions of the different componentsof SS Lep with IR interferometry. We use VINCI/VLTI interferometricobservations in the K band and photometric observations from the UV to thefar-IR. The visibilities are interpreted with simple geometrical models and theSpectral Energy Distribution (SED) is decomposed into the three maincomponents: A star, M star and dust shell/disk. From the SED, we find that themain emitters in the K band are the M star and the circumstellar environment.Both are spatially resolved with the VINCI observations, showing the excess tobe circumbinary and showing the M star to have a size equal to its Roche Lobe.We conclude that we have, for the first time, directly resolved a star fillingits Roche Lobe. The resulting mass transfer is probably the cause of (1) thecircumbinary dust disk of which we see the hot inner region spatially resolvedin our observations, (2) the unusually high luminosity of the A star and (3)the shell spectrum seen in the UV and optical spectra.

Direct diameter measurement of a star filling its Roche Lobe: The semi-detached binary SS Leporis spatially resolved with VINCI/VLTI