Nitrogen-rich field stars have abundance patterns similar to chemically enriched stars in globular clusters (GCs) and are therefore thought to originate from disrupted GCs via tidal stripping or evaporation.
Ellen I. Leitinger and colleagues investigate this scenario by expanding the search for nitrogen-rich field stars in the Kepler field, and find that GCs cannot fully account for the observed population.
The authors compile a sample of red giants and core-helium-burning stars, using APOGEE DR17 for stellar parameters and Gaia DR3 for kinematic properties.
This allows them to identify 13 nitrogen-rich stars that have precisely measured asteroseismic ages from Kepler.
Only three stars are older than 8 billion years, making a GC origin via dynamical ejection or association with younger GCs unlikely for most of the sample.
Nitrogen-rich field stars have abundance patterns similar to chemically enriched stars in globular clusters (GCs) and are therefore thought to originate from disrupted GCs via tidal stripping or evaporation. Ellen I. Leitinger and colleagues investigate this scenario by expanding the search for nitrogen-rich field stars in the Kepler field, and find that GCs cannot fully account for the observed population.
The authors compile a sample of red giants and core-helium-burning stars, using APOGEE DR17 for stellar parameters and Gaia DR3 for kinematic properties. This allows them to identify 13 nitrogen-rich stars that have precisely measured asteroseismic ages from Kepler. Their median age is 1.9 billion years, significantly younger than the typical ages of Galactic GCs. Only three stars are older than 8 billion years, making a GC origin via dynamical ejection or association with younger GCs unlikely for most of the sample.
