The Albedos of Kepler's Close-in super-Earths
arXiv:1405.3798 · doi:10.1088/2041-8205/789/1/L20
Abstract
Exoplanet research focusing on the characterization of super-Earths is currently limited to those handful targets orbiting bright stars that are amenable to detailed study. This Letter proposes to look at alternative avenues to probe the surface and atmospheric properties of this category of planets, known to be ubiquitous in our galaxy. I conduct Markov Chain Monte Carlo lightcurve analyses for 97 Kepler close-in super-Earth candidates with the aim to detect their occultations at visible wavelengths. Brightness temperatures and geometric albedos in the Kepler bandpass are constrained for 27 super-Earth candidates. A hierarchical Bayesian modeling approach is then employed to characterize the population-level reflective properties of these close-in super-Earths. I find median geometric albedos in the Kepler bandpass ranging between 0.16 and 0.30, once decontaminated from thermal emission. These super-Earths geometric albedos are statistically larger than for hot Jupiters, which have medians ranging between 0.06 and 0.11. A subset of objects, including Kepler-10b, exhibit significantly larger albedos (0.4). I argue that a better understanding of the incidence of stellar irradiation on planetary surface and atmospheric processes is key to explain the diversity in albedos observed for close-in super-Earths.
ApJ Letters, in press. 6 pages, 3 figures and 1 table
References in corpus (6)
- A grid of MARCS model atmospheres for late-type stars I. Methods and general properties
- KEPLER's First Rocky Planet: Kepler-10b
- HAT-P-7b: An Extremely Hot Massive Planet Transiting a Bright Star in the Kepler Field
- Chemistry of Silicate Atmospheres of Evaporating Super-Earths
- Inferring the eccentricity distribution
- On the Absorption and Redistribution of Energy in Irradiated Planets
Cited by in corpus (24)
- Calibrating Gyrochronology using Kepler Asteroseismic targets
- Changing Phases of Alien Worlds: Probing Atmospheres of Kepler Planets with High-Precision Photometry
- Planetary Candidates Observed by Kepler V: Planet Sample from Q1-Q12 (36 Months)
- Predictions of the atmospheric composition of GJ 1132b
- Aerosols in Exoplanet Atmospheres
- Advances in exoplanet science from Kepler
- Evidence for a spectroscopic direct detection of reflected light from 51 Peg b
- K2 and Spitzer phase curves of the rocky ultra-short-period planet K2-141 b hint at a tenuous rock vapor atmosphere
- Three Super-Earths Orbiting HD 7924
- An Overabundance of Low-density Neptune-like Planets
- Laboratory spectra of hot molecules: data needs for hot super-Earth exoplanets
- Super-Earths and Earth-like Exoplanets
- Low Albedo Surfaces of Lava Worlds
- Three Temperate Neptunes Orbiting Nearby Stars
- Statistical Eclipses of Close-in Kepler Sub-Saturns
- Multi-season optical modulation phased with the orbit of the super-Earth 55 Cnc e
- Role of magma oceans in controlling carbon and oxygen of sub-Neptune atmospheres
- The TESS-Keck Survey. XV. Precise Properties of 108 TESS Planets and Their Host Stars
- Average Albedos of Close-in Super-Earths and Neptunes from Statistical Analysis of Long Cadence Kepler Secondary Eclipse Data
- 55 Cancri e's occultation captured with CHEOPS
- Exoplanet phase curves at large phase angles. Diagnostics for extended hazy atmospheres
- Probing Kepler's hottest small planets via homogeneous search and analysis of optical secondary eclipses and phase variations
- Refraction in exoplanet atmospheres: Photometric signatures, implications for transmission spectroscopy, and search in Kepler data
- How does the shape of the stellar spectrum affect the Raman scattering features in the albedo of exoplanets?