The Exemplar T8 Subdwarf Companion of Wolf 1130

Autor:	Michael C. Cushing, Ian S. McLean, J. Davy Kirkpatrick, Charles A. Beichman, Christopher R. Gelino, Peter Eisenhardt, Kristin R. Kulas, Gregory N. Mace, Sarah E. Logsdon, Michael F. Skrutskie, Edward L. Wright
Jazyk:	angličtina
Rok vydání:	2013
Předmět:	Physics Proper motion Atmospheric models Metallicity Brown dwarf Binary number FOS: Physical sciences Astronomy and Astrophysics Astrophysics Radius Parameter space Subdwarf Astrophysics - Solar and Stellar Astrophysics Space and Planetary Science Solar and Stellar Astrophysics (astro-ph.SR)
Popis:	We have discovered a wide separation (188.5") T8 subdwarf companion to the sdM1.5+WD binary Wolf 1130. Companionship of WISE J200520.38+542433.9 is verified through common proper motion over a ~3 year baseline. Wolf 1130 is located 15.83 +/- 0.96 parsecs from the Sun, placing the brown dwarf at a projected separation of ~3000 AU. Near-infrared colors and medium resolution (R~2000-4000) spectroscopy establish the uniqueness of this system as a high-gravity, low-metallicity benchmark. Although there are a number of low-metallicity T dwarfs in the literature, WISE J200520.38+542433.9 has the most extreme inferred metallicity to date with [Fe/H] = -0.64 +/- 0.17 based on Wolf 1130. Model comparisons to this exemplar late-type subdwarf support it having an old age, a low metallicity, and a small radius. However, the spectroscopic peculiarities of WISE J200520.38+542433.9 underscore the importance of developing the low-metallicity parameter space of the most current atmospheric models. Accepted to ApJ on 05 September 2013; 33 pages in preprint format, 8 figures, 3 tables
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::4b1c3de56c77aa4d945d497fe469230b http://arxiv.org/abs/1309.1500 Zobrazit plný text záznamu