How to Characterize the Atmosphere of a Transiting Exoplanet

Abstract

This tutorial is an introduction to techniques used to characterize the atmospheres of transiting exoplanets. We intend it to be a useful guide for the undergraduate, graduate student, or postdoctoral scholar who wants to begin research in this field, but who has no prior experience with transiting exoplanets. We begin with a discussion of the properties of exoplanetary systems that allow us to measure exoplanetary spectra, and the principles that underlie transit techniques. Subsequently, we discuss the most favorable wavelengths for observing, and explain the specific techniques of secondary eclipses and eclipse mapping, phase curves, transit spectroscopy, and convolution with spectral templates. Our discussion includes factors that affect the data acquisition, and also a separate discussion of how the results are interpreted. Other important topics that we cover include statistical methods to characterize atmospheres such as stacking, and the effects of stellar activity. We conclude by projecting the future utility of large-aperture observatories such as the James Webb Space Telescope and the forthcoming generation of extremely large ground-based telescopes.

arXiv commentInvited tutorial paper, in press for PASP. 25 pages, 18 figures

References in corpus (180)

• The Transiting Exoplanet Survey Satellite
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Detection of Planetary Transits Across a Sun-like Star
• Detection of an Extrasolar Planet Atmosphere
• A continuum from clear to cloudy hot-Jupiter exoplanets without primordial water depletion
• Clouds in the atmosphere of the super-Earth exoplanet GJ 1214b
• A map of the day-night contrast of the extrasolar planet HD 189733b
• Most 1.6 Earth-Radius Planets are not Rocky
• Theoretical Transmission Spectra During Extrasolar Giant Planet Transits
• A high accuracy computed water line list
• Detection of Thermal Emission from an Extrasolar Planet
• Atmospheric Circulation and Tides of "51Peg b-like" Planets
• A Temperature and Abundance Retrieval Method for Exoplanet Atmospheres
• The Transiting Exoplanet Survey Satellite: Simulations of planet detections and astrophysical false positives
• Infrared Transmission Spectroscopy of the Exoplanets HD209458b and XO-1b Using the Wide Field Camera-3 on the Hubble Space Telescope
• Detection of atmospheric haze on an extrasolar planet: The 0.55 - 1.05 micron transmission spectrum of HD189733b with the Hubble Space Telescope
• The 3.6-8.0 Micron Broadband Emission Spectrum of HD 209458b: Evidence for an Atmospheric Temperature Inversion
• The prevalence of dust on the exoplanet HD 189733b from Hubble and Spitzer observations
• Exoplanet Atmospheres
• The signature of orbital motion from the dayside of the planet tau Bootis b
• Transmission Spectra as Diagnostics of Extrasolar Giant Planet Atmospheres
• Equatorial superrotation on tidally locked exoplanets
• Giant Planets at Small Orbital Distances
• Tidal Evolution of Close-in Extra-Solar Planets
• A ground-based transmission spectrum of the super-Earth exoplanet GJ1214b
• The Transit Light Source Effect: False Spectral Features and Incorrect Densities for M-dwarf Transiting Planets
• Characterizing transiting exoplanet atmospheres with JWST
• A Systematic Retrieval Analysis of Secondary Eclipse Spectra I: A Comparison of Atmospheric Retrieval Techniques
• The Statistics of Albedo and Heat Recirculation on Hot Exoplanets
• Imaging Extrasolar Giant Planets
• Thermal structure of an exoplanet atmosphere from phase-resolved emission spectroscopy
• Friends of Hot Jupiters I: A Radial Velocity Search for Massive, Long-Period Companions to Close-In Gas Giant Planets
• A featureless transmission spectrum for the Neptune-mass exoplanet GJ 436b
• The climate of HD 189733b from fourteen transits and eclipses measured by Spitzer
• High C/O Ratio and Weak Thermal Inversion in the Very Hot Atmosphere of Exoplanet WASP-12b
• 3.6 and 4.5 Micron Phase Curves and Evidence for Non-Equilibrium Chemistry in the Atmosphere of Extrasolar Planet HD 189733b
• Photometric Light Curves and Polarization of Close-in Extrasolar Giant Planets
• How to Distinguish between Cloudy Mini-Neptunes and Water/Volatile-Dominated Super-Earths
• Water Vapor in the Spectrum of the Extrasolar Planet HD 189733b: 1. the Transit
• Transitions in the cloud composition of hot Jupiters
• Transits of Earth-Like Planets
• Transmission Spectra of Three-Dimensional Hot Jupiter Model Atmospheres
• H- Opacity and Water Dissociation in the Dayside Atmosphere of the Very Hot Gas Giant WASP-18 b
• A map of the large day-night temperature gradient of a super-Earth exoplanet
• Compositional diversity in the atmospheres of hot Neptunes, with application to GJ 436b
• Strong Water Absorption in the Dayside Emission Spectrum of the Planet HD 189733b
• Spitzer Secondary Eclipses of the Dense, Modestly-irradiated, Giant Exoplanet HAT-P-20b Using Pixel-Level Decorrelation
• Tau-REx I: A next generation retrieval code for exoplanetary atmospheres
• Finding extraterrestrial life using ground-based high-resolution spectroscopy
• A giant planet undergoing extreme ultraviolet irradiation by its hot massive-star host
• Combining high-dispersion spectroscopy (HDS) with high contrast imaging (HCI): Probing rocky planets around our nearest neighbors
• The phase-dependent Infrared brightness of the extrasolar planet upsilon Andromedae b
• Rotation and winds of exoplanet HD 189733 b measured with high-dispersion transmission spectroscopy
• The Atmospheric Signatures of Super-Earths: How to Distinguish Between Hydrogen-Rich and Hydrogen-Poor Atmospheres
• Observing the Atmospheres of Known Temperate Earth-sized Planets with JWST
• Discovery and Characterization of Transiting SuperEarths Using an All-Sky Transit Survey and Follow-up by the James Webb Space Telescope
• Strong Infrared Emission from the Extrasolar Planet HD189733b
• Periodic Flux Variability of Stars due to the Reflex Doppler Effect Induced by Planetary Companions
• Theory of Extrasolar Giant Planet Transits
• The Influence of Non-Uniform Cloud Cover on Transit Transmission Spectra
• A Spectrum of an Extrasolar Planet
• Global Climate and Atmospheric Composition of the Ultra-Hot Jupiter WASP-103b from HST and Spitzer Phase Curve Observations
• A Systematic Retrieval Analysis of Secondary Eclipse Spectra II: A Uniform Analysis of Eight Planets and Their C to O Ratios
• HAT-P-26b: A Neptune-Mass Exoplanet with a Well Constrained Heavy Element Abundance
• Changing Face of the Extrasolar Giant Planet, HD 209458b
• Inverting Phase Functions to Map Exoplanets
• Atmospheric Circulation of Hot Jupiters: Dayside-Nightside Temperature Differences
• Changing Phases of Alien Worlds: Probing Atmospheres of Kepler Planets with High-Precision Photometry
• Atmospheric Heat Redistribution on Hot Jupiters
• Orbital Phase Variations of the Eccentric Giant Planet HAT-P-2b
• A Two-Dimensional Infrared Map of the Extrasolar Planet HD 189733b
• Carbon monoxide and water vapor in the atmosphere of the non-transiting exoplanet HD 179949 b
• Atmospheric Dynamics of Hot Exoplanets
• Spatially resolved eastward winds and rotation of HD 189733b
• Spitzer Phase Curve Constraints for WASP-43b at 3.6 and 4.5 microns
• Optical Phase Curves of Kepler Exoplanets
• No Thermal Inversion and a Solar Water Abundance for the Hot Jupiter HD209458b from HST WFC3 Emission Spectroscopy
• Transit and Eclipse Analyses of Exoplanet HD 149026b Using BLISS Mapping
• Understanding Trends Associated with Clouds in Irradiated Exoplanets
• An absolute sodium abundance for a cloud-free 'hot Saturn' exoplanet
• Characterizing Transiting Planet Atmospheres through 2025
• Exoplanet Transit Spectroscopy Using WFC3: WASP-12 b, WASP-17 b, and WASP-19 b
• Variability in the super-Earth 55 Cnc e
• HELIOS-Retrieval: An Open-source, Nested Sampling Atmospheric Retrieval Code, Application to the HR 8799 Exoplanets and Inferred Constraints for Planet Formation
• Observations of Exoplanet Atmospheres
• A comprehensive study of Kepler phase curves and secondary eclipses -- temperatures and albedos of confirmed Kepler giant planets
• Detection of Thermal Emission from a Super-Earth
• Towards consistent mapping of distant worlds: secondary-eclipse scanning of the exoplanet HD189733b
• The theory of transmission spectra revisited: a semi-analytical method for interpreting WFC3 data and an unresolved challenge
• Discovery of water at high spectral resolution in the atmosphere of 51 Peg b
• 3.6 and 4.5 $\mu$m $Spitzer$ Phase Curves of the Highly-Irradiated Hot Jupiters WASP-19b and HAT-P-7b
• Detection of the ellipsoidal and the relativistic beaming effects in the CoRoT-3 lightcurve
• Pale Orange Dots: The Impact of Organic Haze on the Habitability and Detectability of Earthlike Exoplanets
• Transit spectroscopy with JWST: Systematics, starspots and stitching
• Near-IR Direct Detection of Water Vapor in Tau Boo b
• Hubble Space Telescope hot Jupiter Transmission Spectral Survey: detection of water in HAT-P-1b from Wide Field Camera 3 near-infrared spatial scan observations
• The Impact of Non-Uniform Thermal Structure on the Interpretation of Exoplanet Emission Spectra
• A Smaller Radius for the Transiting Exoplanet WASP-10b
• Resolving the Surfaces of Extrasolar Planets With Secondary Eclipse Light Curves
• Phase curves of WASP-33b and HD 149026b and a New Correlation Between Phase Curve Offset and Irradiation Temperature
• 3.6 and 4.5 $\mu$m Phase Curves of the Highly-Irradiated Eccentric Hot Jupiter WASP-14b
• Near-infrared Thermal Emission from WASP-12b: detections of the secondary eclipse in Ks, H & J
• Identifying Planetary Biosignature Impostors: Spectral Features of CO and O4 Resulting from Abiotic O2/O3 Production
• Transiting Exoplanet Studies and Community Targets for JWST's Early Release Science Program
• Photometrically derived masses and radii of the planet and star in the TrES-2 system
• Infrared Observations During the Secondary Eclipse of HD 209458 b II. Strong Limits on the Infrared Spectrum Near 2.2 Microns
• Primary and secondary eclipse spectroscopy with JWST: exploring the exoplanet parameter space
• Toward Eclipse Mapping of Hot Jupiters
• Doppler Imaging of Exoplanets and Brown Dwarfs
• Highlights in the Study of Exoplanet Atmospheres
• Glancing views of the Earth. From a lunar eclipse to an exoplanetary transit
• Features in the Broadband Eclipse Spectra of Exoplanets: Signal or Noise?
• Studying atmosphere-dominated hot Jupiter Kepler phase curves: Evidence that inhomogeneous atmospheric reflection is common
• Evidence for a Dayside Thermal Inversion and High Metallicity for the Hot Jupiter WASP-18b
• Strategies for Constraining the Atmospheres of Temperate Terrestrial Planets with JWST
• The astrophysics of visible-light orbital phase curves in the space age
• Statistical Analysis of Hubble/WFC3 Transit Spectroscopy of Extrasolar Planets
• Prospects for Characterizing the Atmosphere of Proxima Centauri b
• The Emergent 1.1-1.7 Micron Spectrum of the Exoplanet CoRoT-2b as Measured Using the Hubble Space Telescope
• Disentangling degenerate solutions from primary transit and secondary eclipse spectroscopy of exoplanets
• Transmission Spectra of Transiting Planet Atmospheres: Model Validation and Simulations of the Hot Neptune GJ 436b for JWST
• Spitzer/MIPS 24 micron Observations of HD 209458b: 3 eclipses, 2.5 transits, and a Phase Curve Corrupted by Instrumental Sensitivity Variations
• Detection of a Westward Hotspot Offset in the Atmosphere of a Hot Gas Giant CoRoT-2b
• Detection of Thermal Emission of XO-2b: Evidence for a Weak Temperature Inversion
• A Characteristic Transmission Spectrum dominated by H${}_2$O applies to the majority of HST/WFC3 exoplanet observations
• Day-side z'-band emission and eccentricity of Wasp-12b
• Warm Spitzer Photometry of XO-4b, HAT-P-6b and HAT-P-8b
• Refined stellar, orbital and planetary parameters of the eccentric HAT-P-2 planetary system
• The secondary eclipse of the transiting exoplanet CoRoT-2b
• A Statistical Comparative Planetology Approach to the Hunt for Habitable Exoplanets and Life Beyond the Solar System
• The mid-infrared spectrum of the transiting exoplanet HD 209458b
• A Sensitive Search for Methane in the Infrared Spectrum of Tau Bootis
• Determining Eccentricities of Transiting Planets: A Divide in the Mass-Period Plane
• The Effects of Refraction on Transit Transmission Spectroscopy: Application to Earth-like Exoplanets
• A cool starspot or a second transiting planet in the TrES-1 system?
• Transiting Exoplanets with JWST
• Simulated JWST/NIRISS Transit Spectroscopy of Anticipated TESS Planets Compared to Select Discoveries from Space-Based and Ground-Based Surveys
• Near-infrared Thermal Emission Detections of a number of hot Jupiters and the Systematics of Ground-based Near-infrared Photometry
• Nightside Pollution of Exoplanet Transit Depths
• Information Content Analysis for Selection of Optimal JWST Observing Modes for Transiting Exoplanet Atmospheres
• Atmospheric Lensing and Oblateness Effects During an Extrasolar Planetary Transit
• On the Method to Infer an Atmosphere on a Tidally-Locked Super Earth Exoplanet and Upper limits to GJ 876d
• Updated Spitzer Emission Spectroscopy of Bright Transiting Hot Jupiter HD189733b
• Accurate parameters of the oldest known rocky-exoplanet hosting system: Kepler-10 revisited
• Spitzer Secondary Eclipse Observations of Five Cool Gas Giant Planets and Empirical Trends in Cool Planet Emission Spectra
• Atmospheric Circulation of Eccentric Hot Jupiter HAT-P-2b
• The Stellar Activity of TRAPPIST-1 and Consequences for the Planetary Atmospheres
• A statistical search for a population of Exo-Trojans in the Kepler dataset
• Spitzer and z' Secondary Eclipse Observations of the Highly Irradiated Transiting Brown Dwarf KELT-1b
• Optical phase curves as diagnostics for aerosol composition in exoplanetary atmospheres
• Bright optical dayside emission from extrasolar planet CoRoT-2b
• High Resolution Transmission Spectroscopy as a Diagnostic for Jovian Exoplanet Atmospheres: Constraints from Theoretical Models
• The Albedos of Kepler's Close-in super-Earths
• Confirming Variability in the Secondary Eclipse Depth of the Super-Earth 55 Cancri e
• The Pale Green Dot: A Method to Characterize Proxima Centauri b using Exo-Aurorae
• Colour-Magnitude Diagrams of Transiting Exoplanets. I - Systems with parallaxes
• Colour-magnitude diagrams of transiting Exoplanets - II. A larger sample from photometric distances
• Discriminating Between Cloudy, Hazy and Clearsky Exoplanets Using Refraction
• Chromospheric Activity of HAT-P-11: an Unusually Active Planet-Hosting K Star
• Clear and Cloudy Exoplanet Forecasts for JWST: Maps, Retrieved Composition and Constraints on Formation with MIRI and NIRCam
• Radial velocity eclipse mapping of exoplanets
• Retrieval Analysis of the Emission Spectrum of WASP-12b: Sensitivity of Outcomes to Prior Assumptions and Implications for Formation History
• Searching for reflected light from $\tau$ Bootis b with high-resolution ground-based spectroscopy: Approaching the $10^{-5}$ contrast barrier
• Analytic Scattering and Refraction Models for Exoplanet Transit Spectra
• Statistical Eclipses of Close-in Kepler Sub-Saturns
• Detection of universality of dark matter profile from Subaru weak lensing measurements of 50 massive clusters
• Refraction in planetary atmospheres: improved analytical expressions and comparison with a new ray-tracing algorithm
• Spitzer Secondary Eclipse Depths with Multiple Intrapixel Sensitivity Correction Methods: Observations of WASP-13b, WASP-15b, WASP-16b, WASP-62b, and HAT-P-22b
• Spotting Stellar Activity Cycles in Gaia Astrometry
• Spectral Resolution-linked Bias in Transit Spectroscopy of Extrasolar Planets
• Near infrared spectroscopic search for the close orbiting planet HD 75289b
• Average Albedos of Close-in Super-Earths and Neptunes from Statistical Analysis of Long Cadence Kepler Secondary Eclipse Data
• Kepler's Dark Worlds: a Low Albedo for an Ensemble of Neptunian and Terran Exoplanets
• A survey of eight hot Jupiters in secondary eclipse using WIRCam at CFHT
• Out-of-Transit Refracted Light in the Atmospheres of Transiting and Non-Transiting Exoplanets
• Detection of the secondary eclipse of Qatar-1b in the Ks band
• Spitzer Secondary Eclipses of Qatar-1b
• Refraction in exoplanet atmospheres: Photometric signatures, implications for transmission spectroscopy, and search in Kepler data
• Phase Curves of the Kepler-11 Multi-Planet System
• Quantifying the Impact of Spectral Coverage on the Retrieval of Molecular Abundances from Exoplanet Transmission Spectra

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• The HST PanCET Program: An Optical to Infrared Transmission Spectrum of HAT-P-32Ab
• Large Interferometer For Exoplanets (LIFE): IX. Assessing the Impact of Clouds on Atmospheric Retrievals at Mid-Infrared Wavelengths with a Venus-Twin Exoplanet
• Emergent Spectral Fluxes of Hot Jupiters: an Abrupt Rise in Day Side Brightness Temperature Under Strong Irradiation
• Ultimate limits of exoplanet spectroscopy: a quantum approach
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• Colour-magnitude diagrams of transiting Exoplanets -- III. A public code, nine strange planets, and the role of Phosphine
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