Betelgeuse’s Hidden Partner: Tracing a Stellar Wake Inside a Supergiant Atmosphere
This paper argues that Betelgeuse’s long secondary period is caused by a companion star orbiting within its extended atmosphere. Optical and ultraviolet spectra show repeating changes in absorption and outflow that match the companion’s six-year orbit. These signatures are best explained by a dense, expanding wake of gas trailing behind the companion as it moves through the star’s chromosphere.
Mapping the Milky Way's DNA: Stellar Parameters and Chemical Abundances Unveiled with S-PLUS
The S-PLUS survey analyzed 5 million Milky Way stars, estimating atmospheric parameters and chemical abundances using machine learning on multi-band photometric data. Neural networks outperformed random forests in accuracy, revealing trends like [Mg/Fe] bimodality and robustly mapping stellar properties. This cost-effective, scalable approach complements spectroscopy, offering new insights into Galactic evolution and paving the way for broader stellar population studies.