APOSTLE Observations of GJ 1214b: System Parameters and Evidence for Stellar Activity

Abstract

We present three transits of GJ 1214b, observed as part of the Apache Point Observatory Survey of Transit Lightcurves of Exoplanets (APOSTLE). We used APOSTLE r-band lightcurves in conjunction with previously gathered data of GJ 1214b to re-derive system parameters. By using parameters such as transit duration and ingress/egress length we are able to reduce the degeneracies between parameters in the fitted transit model, which is a preferred condition for Markov Chain Monte Carlo techniques typically used to quantify uncertainties in measured parameters. The joint analysis of this multi-wavelength dataset confirms earlier estimates of system parameters including planetary orbital period, the planet-to-star radius ratio and stellar density. We fit the photometric spectralenergy distribution of GJ 1214 to derive stellar luminosity, which we then use to derive its absolute mass and radius. From these derived stellar properties and previously published radial velocity data we were able to refine estimates of the absolute parameters for the planet GJ 1214b. Transit times derived from our study show no evidence for strong transit timing variations. Some lightcurves we present show features that we believe are due to stellar activity. During the first night we observed a rise in the out-of-eclipse flux of GJ 1214 with a characteristic fast-rise exponential decay shape commonly associated with stellar flares. On the second night we observed a minor brightening during transit, which we believe might have been caused by the planet obscuring a star-spot on the stellar disk.

10 figure, 4 Tables, submitted to ApJ

References in corpus (33)

• TEMPO2, a new pulsar timing package. I: Overview
• Achieving better than 1 minute accuracy in the Heliocentric and Barycentric Julian Dates
• DHP Framework: Digital Health Passports Using Blockchain -- Use case on international tourism during the COVID-19 pandemic
• Tempo2, a new pulsar timing package. II: The timing model and precision estimates
• Constraining the Age-Activity Relation for Cool Stars: The SDSS DR5 Low-Mass Star Spectroscopic Sample
• Habitable planets around the star Gl 581?
• Improved parameters for extrasolar transiting planets
• Evolution of low-mass star and brown dwarf eclipsing binaries
• Homogeneous studies of transiting extrasolar planets. I. Light curve analyses
• Efficient identification of exoplanetary transit candidates from SuperWASP light curves
• SDSS Standard Star Catalog for Stripe 82: the Dawn of Industrial 1% Optical Photometry
• Hubble Space Telescope times-series photometry of the planetary transit of HD189733: no moon, no rings, starspots
• The Transit Light Curve (TLC) Project. I. Four Consecutive Transits of the Exoplanet XO-1b
• Photometric Variability in Kepler Target Stars. II. An Overview of Amplitude, Periodicity, and Rotation in First Quarter Data
• The Lick-Carnegie Exoplanet Survey: A 3.1 M_Earth Planet in the Habitable Zone of the Nearby M3V Star Gliese 581
• White-light flares on cool stars in the Kepler Quarter 1 Data
• Metal-Rich M-dwarf Planet Hosts: Metallicities with K-Band Spectra
• Analytic Approximations for Transit Light Curve Observables, Uncertainties, and Covariances
• The effect of magnetic activity on low-mass stars in eclipsing binaries
• A White Light Megaflare on the dM4.5e Star YZ CMi
• On the magnetic topology of partially and fully convective stars
• The Transit Light Curve Project. III. Tres Transits of TrES-1
• A Physically-Motivated Photometric Calibration of M Dwarf Metallicity
• The Transit Light Curve Project. XIII. Sixteen Transits of the Super-Earth GJ 1214b
• The Age, Stellar Content and Star Formation Timescale of the B59 Dense Core
• A limit on the presence of Earth-mass planets around a Sun-like star
• Photospheric activity, rotation, and radial velocity variations of the planet-hosting star CoRoT-7
• 2MASS J05162881+2607387: A New Low-Mass Double-Lined Eclipsing Binary
• A cool starspot or a second transiting planet in the TrES-1 system?
• A Tentative Detection of a Starspot During Consecutive Transits of an Extrasolar Planet from the Ground: No Evidence of a Double Transiting Planet System Around TrES-1
• Recent Transits of the Super-Earth Exoplanet GJ 1214b
• Photospheric activity, rotation, and star-planet interaction of the planet-hosting star CoRoT-6
• Magnetic activity in the photosphere of CoRoT-Exo-2a. Active longitudes and short-term spot cycle in a young Sun-like star

Cited by in corpus (43)

• The MUSCLES Treasury Survey I: Motivation and Overview
• The Flat Transmission Spectrum of the Super-Earth GJ1214b from Wide Field Camera 3 on the Hubble Space Telescope
• The Habitability of Planets Orbiting M-dwarf Stars
• The Ultraviolet Radiation Environment Around M dwarf Exoplanet Host Stars
• Observational evidence for a metal rich atmosphere on the super-Earth GJ1214b
• The Hunt for Exomoons with Kepler (HEK): I. Description of a New Observational Project
• Transit Detection in the MEarth Survey of Nearby M Dwarfs: Bridging the Clean-First, Search-Later Divide
• The Atmospheric Chemistry of GJ 1214b: Photochemistry and Clouds
• CARMENES input catalogue of M dwarfs V. Luminosities, colours, and spectral energy distributions
• Tidal Venuses: Triggering a Climate Catastrophe via Tidal Heating
• A Spitzer Transmission Spectrum for the Exoplanet GJ 436b, Evidence for Stellar Variability, and Constraints on Dayside Flux Variations
• Validation of Twelve Small Kepler Transiting Planets in the Habitable Zone
• Formation, Habitability, and Detection of Extrasolar Moons
• Transit timing variations in WASP-10b induced by stellar activity?
• HEK VI: On the Dearth of Galilean Analogs in Kepler and the Exomoon Candidate Kepler-1625b I
• Theoretical Transit Spectra for GJ 1214b and Other "Super-Earths"
• Extrasolar Planet Transits Observed at Kitt Peak National Observatory
• Towards Space-like Photometric Precision from the Ground with Beam-Shaping Diffusers
• Spitzer Transits of the Super-Earth GJ1214b and Implications for Its Atmosphere
• Microphysics of KCl and ZnS Clouds on GJ 1214b
• The Hunt for Exomoons with Kepler (HEK): V. A Survey of 41 Planetary Candidates for Exomoons
• The Transiting System GJ1214: High-Precision Defocused Transit Observations and a Search for Evidence of Transit Timing Variation
• Constraining the atmosphere of GJ 1214b using an optimal estimation technique
• GJ 1214b revised. Improved trigonometric parallax, stellar parameters, orbital solution, and bulk properties for the super-Earth GJ 1214b
• Forecasting the Impact of Stellar Activity on Transiting Exoplanet Spectra
• A Search for Methane in the Atmosphere of GJ 1214b via GTC Narrow-Band Transmission Spectrophotometry
• The Implications of M Dwarf Flares on the Detection and Characterization of Exoplanets at Infrared Wavelengths
• ARES IV: Probing the atmospheres of the two warm small planets HD 106315 c and HD 3167 c with the HST/WFC3 camera
• Discovery of a Transiting Planet Near the Snow-Line
• Narrow-K-Band Observations of the GJ 1214 System
• Large Binocular Telescope view of the atmosphere of GJ1214b
• Optical Observations of the Transiting Exoplanet GJ 1214b
• Know the Planet, Know the Star: Precise Stellar Densities from Kepler Transit Light Curves
• Observations of the WASP-2 System by the APOSTLE Program
• Narrow Band Halpha Photometry of the Super-Earth GJ 1214b with GTC/OSIRIS Tunable Filters
• HD 191939: Three Sub-Neptunes Transiting a Sun-like Star Only 54 pc Away
• Ground-based transit observations of the super-Earth GJ 1214b
• X-ray emission from the super-Earth host GJ 1214
• Analysis of new high-precision transit light curves of WASP-10 b: starspot occultations, small planetary radius, and high metallicity
• APOSTLE: Eleven Transit Observations of TrES-3b
• The Next Generation Transit Survey - Prototyping Phase
• Looking For Timing Variations in the Transits of 16 Exoplanets
• APOSTLE: Longterm Transit Monitoring and Stability Analysis of XO-2b