2002/03/31 by D. Martinez-Delgado, D. Martínez-Delgado, R. Zinn +2 · 2 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1086/341970
16 pages, 2 figures, accepted for ApJ Letters. Some importante changes after revision, including a new figure
arxiv created 2002/05/27 · openalex publication_date 2002/07/01 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/30
Photometry of a large field around the young globular cluster Palomar 12 has revealed the main sequence of a low surface brightness stellar system. This main sequence is indicative of a stellar population that varies significantly in metallicity and/or age but in the mean is more metal-poor than Pal 12. Under different assumptions for the properties of this population, we find distances from the Sun in the range 17-24 kpc, which encompasses the distance to Pal 12, 19.0 ± 0.9 kpc. The stellar system is also detected in a field 2° north of Pal 12, which indicates it has a minimum diameter of ~0.9 kpc. The orbit of Pal 12, the color-magnitude diagram of the stellar system, their positions on the sky, and their distances suggest that they are debris from the tidal disruption of the Sagittarius dwarf spheroidal galaxy. We discuss briefly the implications for the evolution of Sgr and the Galactic halo.