DENSITIES AND ECCENTRICITIES OF 139 KEPLER PLANETS FROM TRANSIT TIME VARIATIONS

By S. Hadden, Y. Lithwick. 2013

154 citations recorded by the source corpus.

We extract densities and eccentricities of 139 sub-Jovian planets by analyzing transit time variations (TTVs) obtained by the Kepler mission through Quarter 12. We partially circumvent the degeneracies that plague TTV inversion with the help of an analytical formula for the TTV. From the observed TTV phases, we find that most of these planets have eccentricities of the order of a few percent. More precisely, the rms eccentricity is , and planets smaller than 2.5 R⊕ are around twice as eccentric as those bigger than 2.5 R⊕. We also find a best-fit density–radius relationship ρ ≈ 3 g cm−3 × (R/3 R⊕)−2.3 for the 56 planets that likely have small eccentricity and hence small statistical correction to their masses. Many planets larger than 2.5 R⊕ are less dense than water, implying that their radii are largely set by a massive hydrogen atmosphere.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/b4d6721c3a084d6910df89e74876ace0c06584d8

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

1. J. Owen
2. Timothy Morton
3. Yanqin Wu
4. E. Petigura
5. B. Fulton
6. Y. Lithwick
7. Andrew W. Howard
8. G. Marcy

In Nuclear and High Energy Physics

1. Yanqin Wu
2. Andrew W. Howard
3. Bonan Pu
4. J. Owen
5. G. Marcy
6. J. Johnson
7. A. Santerne
8. J. Almenara

Citations in the corpus

• ECCENTRICITY FROM TRANSIT PHOTOMETRY: SMALL PLANETS IN KEPLER MULTI-PLANET SYSTEMS HAVE LOW ECCENTRICITIES (2015, background): “Analyzing TTV signals for Kepler planets, Hadden & Lithwick (2014) find an rms eccentricity of 0.018+0.005−0.004.”
• Spacing of Kepler Planets: Sculpting by Dynamical Instability (2015, methodology): “Adopting the measurements by Wu & Lithwick (2013); Hadden & Lithwick (2014) for TTV pairs, σe ≈ 0.02, equation (14) requires that Keff ≥ 12.2.”
• TRANSIT TIMING OBSERVATIONS FROM KEPLER. IX. CATALOG OF THE FULL LONG-CADENCE DATA SET (2016, methodology): “…et al. (2011), (2) Desert et al. (2011), (3) Szabó et al. (2013), (4) Bonomo et al. (2012), (5) Howell et al. (2010), (6) Rowe et al. (2014), (7) Hadden & Lithwick (2014). based follow-up observations (e.g., Raetz et al. 2014), may be very useful for determining the true nature and TTV…”
• One of the closest exoplanet pairs to the 3:2 mean motion resonance: K2-19b and c (2015, background): “Hadden & Lithwick (2014) break this degeneracy statistically, but for individual objects it can be difficult to circumvent (although so-called synodic chopping signals can help, see Nesvorný & Vokrouhlický (2014)).”
• Atmospheric Escape and the Evolution of Close-In Exoplanets (2018, background): “…being entirely solid (e.g. Dressing et al. 2015); in other cases the planet has such a low density that it needs to have a significant (Earth radii or larger) atmosphere composed of Hydrogen/Helium gas (e.g. Wu & Lithwick 2013; Hadden & Lithwick 2014; Weiss & Marcy 2014; Jontof-Hutter et al. 2016).”
• Kepler Planet Masses and Eccentricities from TTV Analysis (2016, background): “We find that planets typically have eccentricities of a few percent or less, in agreement with past statistical studies of multiplanet systems (Wu & Lithwick 2013; Hadden & Lithwick 2014; Van Eylen & Albrecht 2015; Xie et al. 2016).”
• The Evaporation Valley in the Kepler Planets (2017, background): “…measurements of a planet’s radius with a measurement of its mass from transit-timing variations (TTVs, Carter et al. 2012; Wu & Lithwick 2013; Hadden & Lithwick 2014; Jontof-Hutter et al. 2016; Hadden & Lithwick 2016) or radial-velocity (RV) follow-up (e.g. Marcy et al. 2014; Weiss & Marcy…”
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets (2017, background): “In addition, detailed modeling of transit timing variations (TTVs) provided mass constraints for a large number of systems in specific architectures (e.g., Wu & Lithwick 2013; Hadden & Lithwick 2014, 2016).”
• BREEDING SUPER-EARTHS AND BIRTHING SUPER-PUFFS IN TRANSITIONAL DISKS (2015, background): “These constraints — namely, rms eccentricities of 0.018 (Hadden & Lithwick 2014) — are relevant for systems near mean-motion resonance; as such they may not be relevant for run-of-the-mill super-Earths which are not resonant.”