2006/10/18 by L. R. Bedin, G. Piotto, G. Carraro +2 · 45 citations
Physics and Astronomy · #Absolute magnitude #Astrometry #Astronomy and Astrophysical Research #Cluster (spacecraft) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Galaxy cluster #Galaxy groups and clusters #Open cluster #Proper motion #Star cluster #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1051/0004-6361:20066085
published in Astronomy and Astrophysics 460(2), L27-L30 (EDP Sciences) · 5 pages, 3 figures, 3 tables. Accepted for publication in A&A Letters, on October 18th 2006
arxiv created 2006/10/18 · openalex publication_date 2006/10/24 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present improved values of the three components of the absolute space velocity of the open cluster NGC 6791. One HST ACS/WFC field with two-epoch observations provides astrometric measurements of objects in a field containing the cluster center. Identification of 60 background galaxies with sharp nuclei allows us to determine an absolute reference point, and measure the absolute proper motion of the cluster. We find (, )J2000.0 = (, ) mas yr-1, and adopt km s-1 from the average of the published values. Assuming a Galactic potential, we calculate the Galactic orbit of the cluster for various assumed distances, and briefly discuss the implications on the nature and the origin of this peculiar cluster.