TY - JOUR
T1 - Kepler-11 is a Solar Twin
T2 - Revising the Masses and Radii of Benchmark Planets via Precise Stellar Characterization
AU - Bedell, Megan
AU - Bean, Jacob L.
AU - Meléndez, Jorge
AU - Mills, Sean M.
AU - Fabrycky, Daniel C.
AU - Freitas, Fabrício C.
AU - Ramírez, Ivan
AU - Asplund, Martin
AU - Liu, Fan
AU - Yong, David
N1 - Publisher Copyright:
© 2017. The American Astronomical Society. All rights reserved..
PY - 2017/4/20
Y1 - 2017/4/20
N2 - The six planets of the Kepler-11 system are the archetypal example of a population of surprisingly low-density transiting planets revealed by the Kepler mission. We have determined the fundamental parameters and chemical composition of the Kepler-11 host star to unprecedented precision using an extremely high-quality spectrum from Keck-HIRES (R ≃ 67,000, S/N per pixel at 600 nm). Contrary to previously published results, our spectroscopic constraints indicate that Kepler-11 is a young main-sequence solar twin. The revised stellar parameters and new analysis raise the densities of the Kepler-11 planets by between 20% and 95% per planet, making them more typical of the emerging class of "puffy" close-in exoplanets. We obtain photospheric abundances of 22 elements and find that Kepler-11 has an abundance pattern similar to that of the Sun with a slightly higher overall metallicity. We additionally analyze the Kepler light curves using a photodynamical model and discuss the tension between spectroscopic and transit/TTV-based estimates of stellar density.
AB - The six planets of the Kepler-11 system are the archetypal example of a population of surprisingly low-density transiting planets revealed by the Kepler mission. We have determined the fundamental parameters and chemical composition of the Kepler-11 host star to unprecedented precision using an extremely high-quality spectrum from Keck-HIRES (R ≃ 67,000, S/N per pixel at 600 nm). Contrary to previously published results, our spectroscopic constraints indicate that Kepler-11 is a young main-sequence solar twin. The revised stellar parameters and new analysis raise the densities of the Kepler-11 planets by between 20% and 95% per planet, making them more typical of the emerging class of "puffy" close-in exoplanets. We obtain photospheric abundances of 22 elements and find that Kepler-11 has an abundance pattern similar to that of the Sun with a slightly higher overall metallicity. We additionally analyze the Kepler light curves using a photodynamical model and discuss the tension between spectroscopic and transit/TTV-based estimates of stellar density.
KW - planets and satellites: fundamental parameters
KW - stars: abundances
KW - stars: fundamental parameters
KW - techniques: spectroscopic
UR - http://www.scopus.com/inward/record.url?scp=85018957719&partnerID=8YFLogxK
U2 - 10.3847/1538-4357/aa6a1d
DO - 10.3847/1538-4357/aa6a1d
M3 - Article
SN - 0004-637X
VL - 839
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 94
ER -