Spinning Stars: Exploring Rotation Across Stellar Spectral Types
This study examines how stellar rotational velocity varies with spectral type and evolutionary stage. Using data from nearly 50,000 stars, it finds that hot stars (O0 to F2) rotate faster than cool stars (F2 to M9), with rotation slowing significantly as stars evolve. Magnetic braking and stellar winds are key factors in this decline, highlighting how rotation influences a star's lifecycle.
Tracing the Chemical Fingerprints of Early Stars through Elemental Patterns in the Milky Way
This study examines the chemical evolution of elements like carbon, nitrogen, oxygen, and lithium in 52 metal-poor giant stars in the Milky Way’s halo to understand the early Galaxy’s chemical history. By analyzing patterns in “mixed” and “unmixed” stars, the researchers found that mixed stars show evidence of internal processes altering their elemental composition, while unmixed stars retain the chemical signature of the early Galaxy. Lithium detection in some stars supported this classification, and stellar rotation was identified as a crucial factor in explaining observed nitrogen levels.