Volume 472, Number 2, September III 2007
|Page(s)||483 - 488|
|Section||Galactic structure, stellar clusters, and populations|
|Published online||16 July 2007|
FSR 584 – a new globular cluster in the Galaxy?
Universidade Federal do Rio Grande do Sul, Departamento de Astronomia, CP 15051, RS, Porto Alegre 91501-970, Brazil e-mail: [charles;bica]@if.ufrgs.br
2 Università di Padova, Dipartimento di Astronomia, Vicolo dell'Osservatorio 5, 35122 Padova, Italy e-mail: firstname.lastname@example.org
3 Universidade de São Paulo, Departamento de Astronomia, Rua do Matão 1226 São Paulo 05508-900, Brazil e-mail: email@example.com
Accepted: 22 June 2007
Aims.We investigate the nature of the recently catalogued star cluster candidate FSR 584, which is projected in the direction of the molecular cloud W 3 and may be the nearest globular cluster to the Sun.
Methods.2MASS colour-magnitude diagrams, the stellar radial density profile, and proper motions are employed to derive fundamental and structural parameters.
Results.The colour-magnitude diagram morphology and the radial density profile show that FSR 584 is an old star cluster. With proper motions, the properties of FSR 584 are consistent with a metal-poor () globular cluster with a well-defined turnoff and evidence of a blue horizontal-branch. FSR 584 might be a Palomar-like halo globular cluster that is moving towards the Galactic plane, currently at ≈20 pc above it. The distance from the Sun is kpc, and it is located at ≈1 kpc outside the Solar circle. The radial density profile is characterized by a core radius of Rcore pc. However, we cannot exclude the possibility of an old open cluster.
Conclusions.Near-infrared photometry coupled to proper motions support the scenario where FSR 584 is a new globular cluster in the Galaxy. The absorption is , which makes it a limiting object in the optical and explains why it has so far been overlooked.
Key words: Galaxy: globular clusters: individual: FSR 584
© ESO, 2007
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.