Secure mass measurements from transit timing: 10 Kepler exoplanets between 3 and 8 M_⊕ with diverse densities and incident fluxes
Abstract
We infer dynamical masses in eight multiplanet systems using transit times measured from Kepler's complete data set, including short-cadence data where available. Of the 18 dynamical masses that we infer, 10 pass multiple tests for robustness. These are in systems Kepler-26 (KOI-250), Kepler-29 (KOI-738), Kepler-60 (KOI-2086), Kepler-105 (KOI-115), and Kepler-307 (KOI-1576). Kepler-105 c has a radius of 1.3 R_⊕ and a density consistent with an Earth-like composition. Strong transit timing variation (TTV) signals were detected from additional planets, but their inferred masses were sensitive to outliers or consistent solutions could not be found with independently measured transit times, including planets orbiting Kepler-49 (KOI-248), Kepler-57 (KOI-1270), Kepler-105 (KOI-115), and Kepler-177 (KOI-523). Nonetheless, strong upper limits on the mass of Kepler-177 c imply an extremely low density of ~0.1 g cm^(−3). In most cases, individual orbital eccentricities were poorly constrained owing to degeneracies in TTV inversion. For five planet pairs in our sample, strong secular interactions imply a moderate to high likelihood of apsidal alignment over a wide range of possible eccentricities. We also find solutions for the three planets known to orbit Kepler-60 in a Laplace-like resonance chain. However, nonlibrating solutions also match the transit timing data. For six systems, we calculate more precise stellar parameters than previously known, enabling useful constraints on planetary densities where we have secure mass measurements. Placing these exoplanets on the mass–radius diagram, we find that a wide range of densities is observed among sub-Neptune-mass planets and that the range in observed densities is anticorrelated with incident flux.
Additional Information
© 2016 The American Astronomical Society. Received 2015 November 4; accepted 2016 January 28; published 2016 March 16. We wish to thank our anonymous referee for a helpful review that improved this paper. D.J., E.F., and J.L. acknowledge support from NASA Exoplanets Research Program award #NNX15AE21G. The results reported herein benefitted from collaborations and/or information exchange within NASA's Nexus for Exoplanet System Science (NExSS) research coordination network sponsored by NASA's Science Mission Directorate. D.J. and E.F. gratefully acknowledge that this work was partially supported by funding from the Center for Exoplanets and Habitable Worlds. The Center for Exoplanets and Habitable Worlds is supported by the Pennsylvania State University, the Eberly College of Science, and the Pennsylvania Space Grant Consortium. E.A. acknowledges support from NASA grants NNX13AF20G, NNX13AF62G, and NASA Astrobiology Institutes Virtual Planetary Laboratory, supported by NASA under cooperative agreement NNH05ZDA001C. K.D. acknowledges support from the Joint Center for Planetary Astronomy fellowship at Caltech.Attached Files
Published - apj_820_1_39.pdf
Submitted - 1512.02003v2.pdf
Erratum - Jontof-Hutter_2017_ApJ_849_73.pdf
Erratum - Jontof-Hutter_2021_ApJ_911_154.pdf
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Additional details
- Alternative title
- Secure TTV Mass Measurements: Ten Kepler Exoplanets between 3 and 8 Earth Masses with Diverse Densities and Incident Fluxes
- Alternative title
- Secure mass measurements from transit timing: 10 Kepler exoplanets between 3 and 8 M⊕ with diverse densities and incident fluxes
- Eprint ID
- 66501
- Resolver ID
- CaltechAUTHORS:20160427-085910052
- NNX15AE21G
- NASA
- Center for Exoplanets and Habitable Worlds
- Pennsylvania State University
- Eberly College of Science
- Pennsylvania Space Grant Consortium
- NNX13AF20G
- NASA
- NNX13AF62G
- NASA
- NNH05ZDA001C
- NASA
- Caltech Joint Center for Planetary Astronomy Fellowship
- Created
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2016-04-27Created from EPrint's datestamp field
- Updated
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2021-04-29Created from EPrint's last_modified field