ON THE INTERPRETATION OF ß LYRAE AND OTHER CLOSE BINARIES*

BSN. VIII. Detailed Photometric Modeling of Ten W UMa Contact Binaries and a Revised Empirical Period–Mass Relationship

This study continues our ongoing research on contact binary systems by presenting a detailed analysis of 10 targets. Ground-based observations from six different observatories were conducted and used together with TESS data for the analysis process. Photometric data from our observations were reduced with the recently...

Variable Star Bulletin Study of the low-amplitude Z Cam star IX Vel

BS Cassiopeiae: A Contact Binary with Starspot-driven Variability and Evidence for Additional Components

We present a comprehensive photometric and spectroscopic analysis of the contact eclipsing binary BS Cas, based on 22 yr multisite light curves and 2 yr high-resolution spectra. The long-term photometry shows pronounced year-to-year changes in the light-curve shape, including eclipse-depth reversals between the primary...

Revealing the companion of NGC 1850-BH1

The nature of the system NGC 1850-BH1 is discussed controversially in the literature. Located in the young (100 Myr) massive cluster NGC 1850 in the Large Magellanic Cloud, it was initially proposed to consist of a 5 $M_\odot$ main sequence turn-off star orbiting a stellar-mass black hole. However, subsequent analyses...

Measuring the Age and Initial Composition of Interstellar Objects

Measuring the age and composition of interstellar objects is necessary to understand their origins. However, existing methods for measuring the age are either imprecise or require an unusually bright target, while the composition is confounded by the effects of Galactic cosmic rays, which drive chemical reactions in th...

The morphology of contact binary objects in the Solar System

Contact binaries, appearing as two objects stuck together, are prevalent throughout the Solar System, making up between 30-50% of asteroids and comets. Despite this, detailed shape models of contact binaries are hard to obtain remotely, requiring rare occultation events or close approaches to Earth (<0.1 au) to obser...