2006/09/19 by N. Lodieu, N. C. Hambly, R. F. Jameson · 4 citations
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Star Formation Studies #Brown dwarf #Infrared #Photometry (optics) #Physics #Proper motion #Sky #Stars #Stellar classification #Stellar, planetary, and galactic studies #astro-ph
paper · pdf · doi:10.1111/j.1365-2966.2006.10958.x
published as Mon.Not.Roy.Astron.Soc.373:95-104,2006 · 12 pages, 6 figures, 5 tables, accepted to MNRAS
arxiv created 2006/09/19 · openalex publication_date 2006/10/19 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We present the results of a 9.3-deg2 infrared (ZYJHK) survey in the Upper Scorpius association extracted from the UKIRT Infrared Deep Sky Survey (UKIDSS) Galactic Cluster Survey Early Data Release. We have selected a total of 112 candidates from the (Z−J, Z) colour–magnitude diagram over the Z= 12.5–20.5 magnitude range, corresponding to M= 0.25–0.01 M⊙ at an age of 5 Myr and a distance of 145 pc. Additional photometry in J and K filters revealed most of them as reddened stars, leaving 32 possible members. Among them, 15 have proper motion consistent with higher-mass members from Hipparcos and optical spectra with strong Hα in emission and weak gravity features. We have also extracted two lower-mass candidate members for which no optical spectra are in hand. Three members exhibit strong Hα equivalent widths (>20 Å), suggesting that they could still undergo accretion, whereas two other dwarfs show signs of chromospheric activity. The likelihood of the binarity of a couple of new stellar and substellar members is discussed as well.