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
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 ov...
| Autores: | , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , , |
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| Tipo de documento: | artigo |
| Estado: | Versão publicada |
| Data de publicação: | 2013 |
| País: | Brasil |
| Recursos: | Universidade Federal do Rio Grande do Sul (UFRGS) |
| Repositório: | Repositório Institucional da UFRGS |
| Idioma: | inglês |
| OAI Identifier: | oai:www.lume.ufrgs.br:10183/108178 |
| Acesso em linha: | http://hdl.handle.net/10183/108178 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Estrelas binarias Anãs marrons Massa estelar Binaries: spectroscopic Brown dwarfs Stars: individual (HIP 67526) Stars: low-mass Techniques: radial velocities |
| Resumo: | 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. |
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