159 citations · 421 across the 7 of their papers we have counts for
7 papers
Chemical abundances of late-type pre-main sequence stars in the -Orionis cluster
J. I. González Hernández, J. A. Caballero, R. Rebolo +4
The young -Orionis cluster is an important location for understanding the formation and evolution of stars, brown dwarfs, and planetary-mass objects. Its metallicity, although b…
The substellar mass function in sigma Orionis. II. Optical, near-infrared and IRAC/Spitzer photometry of young cluster brown dwarfs and planetary-mass objects
J. A. Caballero, V. J. S. Béjar, R. Rebolo +8
We investigate the mass function in the substellar domain down to a few Jupiter masses in the young sigma Orionis open cluster (3+/-2 Ma, d = 360^+70_-60 pc). We have performed a d…
Are isolated planetary-mass objects really isolated? A brown dwarf-exoplanet system candidate in the sigma Orionis cluster
J. A. Caballero, E. L. Martin, P. D. Dobbie +1
The recent detection by direct imaging of three giant planets at wide separation (50-250 AU) from their primaries has raised the question about the ``true isolation'' of planetary-…
The sigma Orionis substellar population
David Barrado y Navascués, Víctor J. S. Béjar, Reinhard Mundt +4
VLT/FORS spectroscopy and 2MASS near-infrared photometry, together with previously known data, have been used to establish the membership and the properties of a sample of low-mass…
Optical spectroscopy of isolated planetary mass objects in the sigma Orionis cluster
D. Barrado-y-Navascués, M. R. Zapatero-Osorio, V. J. S. Béjar +5
We have obtained low resolution optical spectra of 15 isolated planetary mass objects (IPMOs) in the sigma Orionis cluster, and derived spectral types by comparison with nearby M a…
The Substellar Mass Function in sigma Orionis
V. J. S. Bejar, E. L. Martin, M. R. Zapatero Osorio +7
We combine results from imaging searches for substellar objects in the sigma Orionis cluster and follow-up photometric and spectroscopic observations to derive a census of the brow…