Very low mass stellar and substellar companions to solar-like stars from MARVELS. V. A low eccentricity brown dwarf from the driest part of the desert, marvels-6b

• Autor(a) principal: De Lee, Nathan M.
• Data de Publicação: 2013
• Outros Autores: Ge, Jian, Crepp, Justin R., Eastman, Jason, Esposito, Massimiliano, Femenía Castellá, B., Fleming, S.W., Gaudi, B. S., Ghezzi, Luan, González Hernández, Jonay I., Lee, Brian L., Stassun, Keivan G., Wisniewski, J.P., Wood-Vasey, W.M., Agol, Eric, Allende Prieto, Carlos, Barnes, Rory, Bizyaev, D., Cargile, Phillip A., Chang, Liang, Costa, Luiz N. da, Mello, Gustavo Frederico Porto de, Ferreira, Letícia D., Gary, Bruce L., Hebb, Leslie, Holtzman, J.A., Liu, Jian, Ma, Bo, Mack, C. E., Mahadevan, Suvrath, Maia, Marcio Antonio Geimba, Nguyen, D.C., Oravetz, Audrey, Oravetz, Daniel J., Paegert, Martin, Pan, K., Pepper, J., Malanushenko, E., Malanushenko, V., Rebolo, Rafael, Santiago, Basilio Xavier, Schneider, D.P., Bradley, Alaina C. Shelden, Wan, Xiaoke, Wang, Ji, Zhao, Bo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/108158
• topic: Estrelas binarias; Espectros estelares; Anãs marrons; Massa estelar; Movimento estelar; Rotacao estelar; Dimensões estelares; Brown dwarfs; Stars: individual (GSC 03546-01452)

We describe the discovery of a likely brown dwarf (BD) companion with a minimum mass of 31.7 ± 2.0 MJup to GSC 03546-01452 from the MARVELS radial velocity survey, which we designate as MARVELS-6b. For reasonable priors, our analysis gives a probability of 72% that MARVELS-6b has a mass below the hydrogen-burning limit of 0.072M , and thus it is a high-confidence BDcompanion. It has amoderately long orbital period of 47.8929+0.0063 −0.0062 days with a low eccentricity of 0.1442+0.0078 −0.0073, and a semi-amplitude of 1644+12 −13 m s−1. Moderate resolution spectroscopy of the host star has determined the following parameters: Teff = 5598 ± 63, log g = 4.44 ± 0.17, and [Fe/H] = +0.40 ± 0.09. Based upon these measurements, GSC 03546-01452 has a probable mass and radius of M∗ = 1.11±0.11M and R∗ = 1.06±0.23R with an age consistent with less than ∼6 Gyr at a distance of 219 ± 21 pc from the Sun. Although MARVELS-6b is not observed to transit, we cannot definitively rule out a transiting configuration based on our observations. There is a visual companion detected with Lucky Imaging at 7. 7 from the host star, but our analysis shows that it is not bound to this system. The minimum mass of MARVELS-6b exists at the minimum of the mass functions for both stars and planets, making this a rare object even compared to other BDs. It also exists in an underdense region in both period/eccentricity and metallicity/eccentricity space.