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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We aim at determining the masses of Cepheids in binary systems, as well astheir geometric distances and the flux contribution of the companions. Thecombination of interferometry with spectroscopy will offer a unique andindependent estimate of the Cepheid masses. Using long-baseline interferometryat visible and infrared wavelengths, it is possible to spatially resolve binarysystems containing a Cepheid down to milliarcsecond separations. Based on theresulting visual orbit and radial velocities, we can then derive thefundamental parameters of these systems, particularly the masses of thecomponents and the geometric distance. We therefore performed interferometricobservations of the first-overtone mode Cepheid V1334 Cyg with the CHARA/MIRCcombiner. We report the first detection of a Cepheid companion usinglong-baseline interferometry. We detect the signature of a companion orbitingV1334 Cyg at two epochs. We measure a flux ratio between the companion and theCepheid f = 3.10+/-0.08%, giving an apparent magnitude mH = 8.47+/-0.15mag. Thecombination of interferometric and spectroscopic data have enabled the uniquedetermination of the orbital elements: P = 1938.6+/-1.2 days, Tp = 2 443616.1+/-7.3, a = 8.54+/-0.51mas, i = 124.7+/-1.8{\deg}, e = 0.190+/-0.013,{\omega} = 228.7+/-1.6{\deg}, and {\Omega} = 206.3+/-9.4{\deg}. We derive aminimal distance d ~ 691 pc, a minimum mass for both stars of 3.6 Msol, with aspectral type earlier than B5.5V for the companion star. Our measured fluxratio suggests that radial velocity detection of the companion usingspectroscopy is within reach, and would provide an orbital parallax andmodel-free masses.

Multiplicity of Galactic Cepheids from long-baseline interferometry I. CHARA/MIRC detection of the companion of V1334 Cygni