2009/02/26 by L. Spezzi, I. Pagano, G. Marino +12
Physics and Astronomy · #Astronomy #Astrophysics #Astrophysics and Star Formation Studies #Cluster (spacecraft) #Debris disk #Galaxies: Formation, Evolution, Phenomena #Infrared excess #Limiting magnitude #Open cluster #Photometry (optics) #Physics #Planetary system #Spitzer Space Telescope #Stars #Stellar classification #Stellar, planetary, and galactic studies #Telescope #astro-ph.SR
paper · pdf · doi:10.1051/0004-6361/200810609
17 pages, 9 figures
arxiv created 2009/02/26 · openalex publication_date 2009/04/01 · arxiv updated 2015/05/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
<i>Aims. <i/>We report the outcome of a deep multiwavelength study of the IC 2391 young open cluster. We attempt to uncover new low-mass and sub-stellar members of the cluster and identify new debris disk objects.<i>Methods. <i/>We observed a 30 30 square arcmin area in IC 2391 using the wide-field imager at the ESO 2.2 m telescope. The completeness limits of the photometry at the 3<i>σ<i/> level are <i>V<i/> = 24.7, <i>R<i/><sub>C<sub/> = 23.7, and <i>I<i/><sub>C<sub/> = 23.0, faint enough to reveal sub-stellar members down to ~0.03 . Our membership criteria are based on use of our optical data in combination with magnitudes from the 2MASS catalog. We also estimate the physical parameters of the selected candidates. Debris disk candidates are identified on the basis of their infrared excess emission using near- and mid-infrared photometry from the Spitzer Space Telescope.<i>Results. <i/>Our optical survey, which has a limiting magnitude at the 3<i>σ<i/> level 1–2 mag fainter than previous optical surveys conducted in IC 2391, revealed 29 new low-mass member candidates of the cluster. We estimate the contamination to be at least ~50%. We constrain the fraction of sub-stellar objects in the range 8–15% and discuss possible explanations of the deficit of brown dwarfs in this cluster. We also identify 10 candidates in the cluster showing IR excess emission consistent with the presence of debris disks.