1. Characterization of the gaseous companion κ Andromedae b. New Keck and LBTI high-contrast observations
- Author
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M. Bonnefoy, T. Currie, G.-D. Marleau, J. E. Schlieder, J. Wisniewski, J. Carson, K. R. Covey, T. Henning, B. Biller, P. Hinz, H. Klahr, A. N. Marsh Boyer, N. Zimmerman, M. Janson, M. McElwain, C. Mordasini, A. Skemer, V. Bailey, D. Defrère, C. Thalmann, M. Skrutskie, F. Allard, D. Homeier, M. Tamura, M. Feldt, A. Cumming, C. Grady, W. Brandner, C. Helling, S. Witte, P. Hauschildt, R. Kandori, M. Kuzuhara, M. Fukagawa, J. Kwon, T. Kudo, J. Hashimoto, N. Kusakabe, L. Abe, T. Brandt, S. Egner, O. Guyon, Y. Hayano, M. Hayashi, S. Hayashi, K. Hodapp, M. Ishii, M. Iye, G. Knapp, T. Matsuo, K. Mede, M. Miyama, J.-I. Morino, A. Moro-Martin, T. Nishimura, T. Pyo, E. Serabyn, T. Suenaga, H. Suto, R. Suzuki, null Takahashi, M. Takami, N. Takato, H. Terada, D. Tomono, E. Turner, M. Watanabe, T. Yamada, H. Takami, T. Usuda, Science & Technology Facilities Council, University of St Andrews. School of Physics and Astronomy, and Low Energy Astrophysics (API, FNWI)
- Subjects
individual: kappa Andromedae [Stars] ,Gas giant ,Brown dwarf ,Astrophysics ,Photometry (optics) ,Extrasolar giant planets ,QB Astronomy ,Diretly imaged planet ,Low-mass stars ,Adaptive-optics system ,Beta-Pictoris B ,QB ,Physics ,Direct-imaging discovery ,Stellar kinematic groups ,Finding campaign discovery ,Atmospheric models ,photometric [Techniques] ,Astronomy and Astrophysics ,Mass ratio ,Surface gravity ,Brown dwarf companion ,adaptive optics [Instrumentation] ,Planetary systems ,Astrophysics - Solar and Stellar Astrophysics ,13. Climate action ,Space and Planetary Science ,Spectral energy distribution ,Young solar analog ,Low Mass ,Astrophysics - Earth and Planetary Astrophysics - Abstract
We previously reported the direct detection of a low mass companion at a projected separation of 55+-2 AU around the B9 type star {\kappa} Andromedae. The properties of the system (mass ratio, separation) make it a benchmark for the understanding of the formation and evolution of gas giant planets and brown dwarfs on wide-orbits. We present new angular differential imaging (ADI) images of the Kappa Andromedae system at 2.146 (Ks), 3.776 (L'), 4.052 (NB 4.05) and 4.78 {\mu}m (M') obtained with Keck/NIRC2 and LBTI/LMIRCam, as well as more accurate near-infrared photometry of the star with the MIMIR instrument. We derive a more accurate J = 15.86 +- 0.21, H = 14.95 +- 0.13, Ks = 14.32 +- 0.09 mag for {\kappa} And b. We redetect the companion in all our high contrast observations. We confirm previous contrasts obtained at Ks and L' band. We derive NB 4.05 = 13.0 +- 0.2 and M' = 13.3 +- 0.3 mag and estimate Log10(L/Lsun) = -3.76 +- 0.06. We build the 1-5 microns spectral energy distribution of the companion and compare it to seven PHOENIX-based atmospheric models in order to derive Teff = 1900+100-200 K. Models do not set constrains on the surface gravity. ``Hot-start" evolutionary models predict masses of 14+25-2 MJup based on the luminosity and temperature estimates, and considering a conservative age range for the system (30+120-10 Myr). ``warm-start" evolutionary tracks constrain the mass to M >= 11 MJup. Therefore, the mass of {\kappa} Andromedae b mostly falls in the brown-dwarf regime, due to remaining uncertainties in age and mass-luminosity models. According to the formation models, disk instability in a primordial disk could account for the position and a wide range of plausible masses of {\kappa} And b., Comment: 20 pages, 16 figures, accepted for publication in Astronomy and Astrophysics on August 6, 2013
- Published
- 2014