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

Some close binaries of the beta Lyrae type show photometric cycles longerthan the orbital one, which are possibly related to changes in their accretiondisks. We aim to understand the short- and long-scale changes observed in thelight curve of the eclipsing system OGLE-BLG-ECL-157529. In particular, we wantto shed light on the contribution of the disk to these changes, especiallythose related to the long cycle, occurring on timescales of hundreds of days.We studied I-band OGLE photometric times series spanning 18.5 years,constructing disk models by analyzing the orbital light curve at 52 consecutiveepochs. An optimized simplex algorithm was used to solve the inverse problem byadjusting the light curve with the best stellar-orbital-disk parameters for thesystem. We applied principal components analysis to the parameters to evaluatetheir dependence and variability. We constructed a description of the masstransfer rate in terms of disk parameters. We find that the light variabilitycan be understood in terms of a variable mass transfer rate and variableaccretion disk. The system brightness at orbital phase 0.25 follows the longcycle and is correlated with the mass transfer rate and the disk thickness. Thelong-cycle brightness variations can be understood in terms of differentialoccultation of the hotter star by a disk of variable thickness. Our model fitsthe overall light curve during 18.5 years well, including epochs of reversal ofmain and secondary eclipse depths. The disk radius cyclically change around thetidal radius, decoupled from changes in the mass transfer rate or systembrightness, suggesting that viscous delay might explain the non-immediateresponse. Although the disk is large and fills a large fraction of the hot starRoche lobe, Lindblad resonance are far beyond the disk, excluding viscousdissipation as a major source of photometric variability.

Model for the long and orbital brightness variability of the $\beta$ Lyrae type binary OGLE-BLG-ECL-157529