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

We present detailed analyses of updated eclipse timing diagrams for 32contact binary merger candidates in the Galactic bulge. The photometric datawas obtained from 2016 to 2021 using the Korea Microlensing Telescope Network(KMTNet) with the 1.6 m telescopes located at three southern sites (CTIO, SAAO,and SSO). The times of minimum lights were determined by applying the binarystar model to full light curves created at half-year intervals from theobservations. The orbital period variations of the binary systems were analyzedusing the $O-C$ diagrams from our new timings with the others published in theliterature (Hong et al.), which are based on the OGLE observations from 2001 to2015. As results, the orbital periods and period decreasing rates of 32 binarysystems were located to be in the ranges of 0.370$-$1.238 days and from $-3.0$to $-13.1\times10^{-6}$ day yr$^{-1}$, respectively. Out of these stars, 24systems show a combination effect of a parabola and a light travel time causedby a third body and their outer orbital periods are in the range of 9.1$-$26.5yr, respectively. We propose that all of our merger candidates need additionalmonitoring observations to study a luminous red nova (LRN) progenitor.

Improved period variations of 32 contact binaries with rapidly decreasing periods in the Galactic Bulge