# Mass, Density, and Formation Constraints in the Compact, Sub-Earth Kepler-444 System including Two Mars-mass Planets

@article{Mills2017MassDA,
title={Mass, Density, and Formation Constraints in the Compact, Sub-Earth Kepler-444 System including Two Mars-mass Planets},
author={Sean M. Mills and Daniel C. Fabrycky},
journal={The Astrophysical Journal},
year={2017},
volume={838}
}
• Published 9 March 2017
• Physics, Geology
• The Astrophysical Journal
Kepler-444 is a five planet system around a host-star approximately 11 billion years old. The five transiting planets all have sub-Earth radii and are in a compact configuration with orbital periods between 3 and 10 days. Here we present a transit-timing analysis of the system using the full Kepler data set in order to determine the masses of the planets. Two planets, Kepler-444 d ($M_\mathrm{d}=0.036^{+0.065}_{-0.020}M_\oplus$) and Kepler-444 e ($M_\mathrm{e}=0.034^{+0.059}_{-0.019}M_\oplus… 19 Citations ## Figures and Tables from this paper The Discovery of the Long-Period, Eccentric Planet Kepler-88 d and System Characterization with Radial Velocities and Photodynamical Analysis • Physics, Geology The Astronomical Journal • 2020 We present the discovery of Kepler-88 d ($P_d = 1403\pm14$days,$M\mathrm{sin}i_d = 965\pm44\,M_\oplus = 3.04\pm0.14\,M_J$,$e_d = 0.41\pm0.03\$) based on six years of radial velocity (RV) follow-up
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