Kepler-90: Giant Transit-timing Variations Reveal a Super-puff

  title={Kepler-90: Giant Transit-timing Variations Reveal a Super-puff},
  author={Yan Liang and Jakob Robnik and Uros Seljak},
  journal={The Astronomical Journal},
Exoplanet transit-timing variations (TTVs) caused by gravitational forces between planets can be used to determine planetary masses and orbital parameters. Most of the observed TTVs are small and sinusoidal in time, leading to degeneracies between the masses and orbital parameters. Here we report a TTV analysis of Kepler-90g and Kepler-90h, which exhibit large TTVs up to 25 hr. With optimization, we find a unique solution that allows us to constrain all of the orbital parameters. The best-fit… 

WASP-107b’s Density Is Even Lower: A Case Study for the Physics of Planetary Gas Envelope Accretion and Orbital Migration

With a mass in the Neptune regime and a radius of Jupiter, WASP-107b presents a challenge to planet formation theories. Meanwhile, the planet’s low surface gravity and the star’s brightness also make

Grain Growth in Escaping Atmospheres: Implications for the Radius Inflation of Super-Puffs

Super-puffs—low-mass exoplanets with extremely low bulk density—are attractive targets for exploring their atmospheres and formation processes. Recent studies suggested that the large radii of

Matched filtering with non-Gaussian noise for planet transit detections

We develop a method for planet detection in transit data, which is based on the matched filter technique, combined with the Gaussianization of the noise outliers. The method is based on Fourier



Refining the Transit-timing and Photometric Analysis of TRAPPIST-1: Masses, Radii, Densities, Dynamics, and Ephemerides

We have collected transit times for the TRAPPIST-1 system with the Spitzer Space Telescope over four years. We add to these ground-based, HST, and K2 transit-time measurements, and revisit an N-body

Dynamics of Systems of Two Close Planets

Abstract In connection with the study of newly formed protoplanetary embryos in the early Solar System, we study the dynamics of a pair of interacting planets orbiting a Sun. By examining the

Very Low Density Planets around Kepler-51 Revealed with Transit Timing Variations and an Anomaly Similar to a Planet-Planet Eclipse Event

We present an analysis of the transit timing variations (TTVs) in the multi-transiting planetary system around Kepler-51 (KOI-620). This system consists of two confirmed transiting planets,

DHP Framework: Digital Health Passports Using Blockchain - Use case on international tourism during the COVID-19 pandemic

The DHP Framework is presented that uses a private blockchain and Proof of Authority for issuing Digital Health Passports and discusses the concept of a Health Passport as a means of verifying that individuals are disease risk-free and how it could be used to resume the international tourism sector.

Kepler Data Processing Handbook: Transiting Planet Search

Sub-Neptune formation: the view from resonant planets

The orbital period ratios of neighbouring sub-Neptunes are distributed asymmetrically near first-order resonances. There are deficits of systems---"troughs" in the period ratio histogram---just short

Exploring Whether Super-puffs can be Explained as Ringed Exoplanets

An intriguing, growing class of planets are the “super-puffs,” objects with exceptionally large radii for their masses and thus correspondingly low densities (≲0.3 g cm−3). Here we consider whether

Kepler Data Analysis: Non-Gaussian Noise and Fourier Gaussian Process Analysis of Stellar Variability

A statistical analysis model of Kepler stellar flux data in the presence of planet transits, non-Gaussian noise, and stellar variability is developed, which gives a better match to the stellar variability than the existing methods, and robustly handles noise outliers.

dynesty: a dynamic nested sampling package for estimating Bayesian posteriors and evidences

  • J. Speagle
  • Computer Science
    Monthly Notices of the Royal Astronomical Society
  • 2020
Dynesty, a public, open-source, python package to estimate Bayesian posteriors and evidences (marginal likelihoods) using the dynamic nested sampling methods developed by Higson et al, can provide substantial improvements in sampling efficiency compared to popular MCMC approaches in the astronomical literature.

Dusty Outflows in Planetary Atmospheres: Understanding “Super-puffs” and Transmission Spectra of Sub-Neptunes

“Super-puffs” are planets with anomalously low mean densities ( ). With a low surface gravity, the extended atmosphere is susceptible to extreme hydrodynamic mass loss (“boil-off”) on a timescale