Tracking Galactic Motions: Shapes and Tilts of Stellar Velocity Patterns
Dmytrenko et al. analyze velocity ellipsoids of red giants and subgiants from Gaia DR3, uncovering kinematic distortions like the Galactic warp and non-axisymmetric features. They find that ellipsoid shapes and orientations vary with Galactocentric distance, reflecting gravitational influences and anisotropic stellar motions. This study provides detailed insights into the Milky Way's complex dynamics beyond the solar neighborhood.
What Happens When Giant Stars Encounter Black Holes? Understanding Partial Tidal Disruption Events
Giant stars undergoing Partial Tidal Disruption Events (PTDEs) near black holes lose parts of their envelopes but retain their dense cores. These remnants quickly re-expand into giant-like structures, often brighter than stars of similar mass. Repeated PTDEs gradually strip more mass, creating lighter giants without significantly altering their lifetimes. Observing such remnants near galactic centers could reveal past black hole activity and stellar dynamics.