A Double Main Sequence in the Globular Cluster NGC 6397

Bibcode
2012ApJ...745...27M
DOI
10.1088/0004-637X/745/1/27
Milone, A. P.; Marino, A. F.; Piotto, G.; Bedin, L. R.; Anderson, J.; Aparicio, A.; Cassisi, S.; Rich, R. M.
Referencia bibliográfica

The Astrophysical Journal, Volume 745, Issue 1, article id. 27 (2012).

Fecha de publicación:
1
2012
Revista
The Astrophysical Journal
Número de autores
8
Número de autores del IAC
2
Número de citas
92
Número de citas referidas
87
Descripción
High-precision multi-band Hubble Space Telescope (HST) photometry reveals that the main sequence of the globular cluster NGC 6397 splits into two components, containing ~30% and ~70% of the stars. This double sequence is consistent with the idea that the cluster hosts two stellar populations: (1) a primordial population that has a composition similar to field stars, containing ~30% of the stars, and (2) a second generation with enhanced sodium and nitrogen, depleted carbon and oxygen, and a slightly enhanced helium abundance (ΔY ~ 0.01). We examine the color difference between the two sequences across a variety of color baselines and find that the second sequence is anomalously faint in m F336W. Theoretical isochrones indicate that this could be due to NH depletion. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS 5-26555.
Proyectos relacionados
Cúmulo Globular NGC 2808
Vía Láctea y galaxias cercanas

El objetivo general del Proyecto es el estudio de la estructura, historia evolutiva y proceso de formación de galaxias a través de sus poblaciones estelares resueltas, tanto a partir de fotometría como espectroscopia. El proyecto puede dividirse en cuatro líneas principales: I. Historia de formación estelar en el Grupo Local. El objetivo de esta

Martín
López Corredoira
Cerrado
Tipo
Con árbitro
La Vía Láctea y el Grupo Local (MWLG)

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