Very low mass stellar and substellar companions to solar-like stars from MARVELS. IV. A candidate bronw dwarf or low-mass stellar companion HIP 67526

• Autor(a) principal: Jiang, Peng
• Data de Publicação: 2013
• Outros Autores: Ge, Jian, Cargile, Phillip A., Crepp, Justin R., De Lee, Nathan M., Mello, Gustavo Frederico Porto de, Esposito, Massimiliano, Ferreira, Letícia D., Femenía Castellá, B., Fleming, S.W., Gaudi, B. S., Ghezzi, Luan, González Hernández, Jonay I., Hebb, Leslie, Lee, Brian L., Ma, Bo, Stassun, Keivan G., Wang, Ji, Wisniewski, J.P., Agol, Eric, Bizyaev, D., Brewington, Howard J., Chang, Liang, Costa, Luiz N. da, Eastman, Jason, Ebelke, Garrett L., Gary, Bruce L., Kane, Stephen R., Li, Rui, Liu, Jian, Mahadevan, Suvrath, Maia, Marcio Antonio Geimba, Malanushenko, V., Malanushenko, E., Muna, Demitri, Nguyen, D.C., Ogando, Ricardo L.C., Oravetz, Audrey, Oravetz, Daniel J., Pan, K., Pepper, J., Paegert, Martin, Allende Prieto, Carlos, Rebolo, Rafael, Santiago, Basilio Xavier, Schneider, D.P., Bradley, Alaina C. Shelden, Sivarani, Thirupathi, Snedden, S.A., Van Eyken, Julian C., Wan, Xiaoke, Weaver, Benjamin A., Zhao, Bo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFRGS
• Texto Completo: http://hdl.handle.net/10183/108178
• topic: Estrelas binarias; Anãs marrons; Massa estelar; Binaries: spectroscopic; Brown dwarfs; Stars: individual (HIP 67526); Stars: low-mass; Techniques: radial velocities

We report the discovery of a candidate brown dwarf (BD) or a very low mass stellar companion (MARVELS-5b) to the star HIP 67526 from the Multi-object Apache point observatory Radial Velocity Exoplanet Large-area Survey (MARVELS). The radial velocity curve for this object contains 31 epochs spread over 2.5 yr.OurKeplerian fit, using a Markov Chain Monte Carlo approach, reveals that the companion has an orbital period of 90.2695+0.0188 −0.0187 days, an eccentricity of 0.4375±0.0040, and a semi-amplitude of 2948.14+16.65 −16.55 m s−1. Using additional high-resolution spectroscopy, we find the host star has an effective temperature Teff = 6004 ± 34 K, a surface gravity log g (cgs) = 4.55 ± 0.17, and a metallicity [Fe/H] = +0.04 ± 0.06. The stellar mass and radius determined through the empirical relationship of Torres et al. yields 1.10±0.09M and 0.92±0.19R . The minimummass ofMARVELS- 5b is 65.0±2.9MJup, indicating that it is likely to be either a BD or a very low mass star, thus occupying a relatively sparsely populated region of the mass function of companions to solar-type stars. The distance to this system is 101 ± 10 pc from the astrometric measurements of Hipparcos. No stellar tertiary is detected in the high-contrast images taken by either FastCam lucky imaging or Keck adaptive optics imaging, ruling out any star with mass greater than 0.2 M at a separation larger than 40 AU.