A Unified Spectroscopic and Photometric Model to Infer Surface Inhomogeneity: Application to Luhman 16B
arXiv:2206.01770 · doi:10.3847/1538-4357/ac75b9
Abstract
Extremely large telescopes (ELTs) provide an opportunity to observe surface inhomogeneities for ultracool objects including M dwarfs, brown dwarfs (BDs), and gas giant planets via Doppler imaging and spectro-photometry techniques. These inhomogeneities can be caused by star spots, clouds, and vortices. Star spots and associated stellar flares play a significant role in habitability, either stifling life or catalyzing abiogenesis depending on the emission frequency, magnitude, and orientation. Clouds and vortices may be the source of spectral and photometric variability observed at the L/T transition of BDs and are expected in gas giant exoplanets. We develop a versatile analytical framework to model and infer surface inhomogeneities which can be applied to both spectroscopic and photometric data. This model is validated against a slew of numerical simulations. Using archival spectroscopic and photometric data, we infer star spot parameters (location, size, and contrast) and generate global surface maps for Luhman 16B (an early T dwarf and one of our solar system's nearest neighbors at a distance of approximately 2 pc). We confirm previous findings that Luhman 16B's atmosphere is inhomogeneous with time-varying features. In addition, we provide tentative evidence of longer timescale atmospheric structures such as dark equatorial and bright mid-latitude to polar spots. These findings are discussed in the context of atmospheric circulation and dynamics for ultracool dwarfs. Our analytical model will be valuable in assessing the feasibility of using ELTs to study surface inhomogeneities of gas giant exoplanets and other ultracool objects.
arXiv comment23 pages, 10 figures, 1 table. Accepted for publication in The Astrophysical Journal
References in corpus (98)
- SciPy 1.0--Fundamental Algorithms for Scientific Computing in Python
- dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
- Habitable Zones Around Main-Sequence Stars: New Estimates
- Evolutionary models for very-low-mass stars and brown dwarfs with dusty atmospheres
- The Limiting Effects of Dust in Brown Dwarf Model Atmospheres
- Precipitating Condensation Clouds in Substellar Atmospheres
- Detection of Carbon Monoxide and Water Absorption Lines in an Exoplanet Atmosphere
- L and T Dwarf Models and the L to T Transition
- Least squares deconvolution of the stellar intensity and polarization spectra
- Clouds and Chemistry: Ultracool Dwarf Atmospheric Properties from Optical and Infrared Colors
- Clouds and Chemistry in the Atmosphere of Extrasolar Planet HR8799b
- A Re-appraisal of the Habitability of Planets Around M Dwarf Stars
- Stellar Flares from the First Tess Data Release: Exploring a New Sample of M-dwarfs
- STARRY: Analytic Occultation Light Curves
- Atmospheric Parameters of Field L and T Dwarfs
- A Combined Subaru/VLT/MMT 1--5 Micron Study of Planets Orbiting HR 8799: Implications for Atmospheric Properties, Masses, and Formation
- Masses, Radii, and Cloud Properties of the HR 8799 Planets
- Weather on Other Worlds. II. Survey Results: Spots Are Ubiquitous on L and T Dwarfs
- Chromospheric Activity, Rotation, and Rotational Braking in M and L Dwarfs
- Evidence for Cloud Disruption in the L/T Dwarf Transition
- HST Spectral Mapping of L/T Transition Brown Dwarfs Reveals Cloud Thickness Variations
- Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
- An Increase in the Mass of Planetary Systems around Lower-Mass Stars
- A Patchy Cloud Model for the L to T Dwarf Transition
- Large Amplitude Variations of an L/T Transition Brown Dwarf: Multi-Wavelength Observations of Patchy, High-Contrast Cloud Features
- A global cloud map of the nearest known brown dwarf
- Strong Brightness Variations Signal Cloudy-to-Clear Transition of Brown Dwarfs
- Ammonia as a tracer of chemical equilibrium in the T7.5 dwarf Gliese 570D
- Individual Dynamical Masses of Ultracool Dwarfs
- Simultaneous Detection of Water, Methane and Carbon Monoxide in the Atmosphere of Exoplanet HR8799b
- Discovery of a Binary Brown Dwarf at 2 Parsecs from the Sun
- Improved Modeling of the Rossiter-McLaughlin Effect for Transiting Exoplanets
- The Origin of RNA Precursors on Exoplanets
- Model atmospheres for massive gas giants with thick clouds: Application to the HR 8799 planets and predictions for future detections
- Molecular Abundances in the Atmosphere of the T Dwarf Gl 229B
- The Spectrum of the Brown Dwarf Gliese 229B
- Atmospheric dynamics of brown dwarfs and directly imaged giant planets
- The CARMENES search for exoplanets around M dwarfs -- Planet occurrence rates from a subsample of 71 stars
- HELIOS-Retrieval: An Open-source, Nested Sampling Atmospheric Retrieval Code, Application to the HR 8799 Exoplanets and Inferred Constraints for Planet Formation
- Vertical Atmospheric Structure in a Variable Brown Dwarf: Pressure-dependent Phase Shifts in Simultaneous Hubble Space Telescope-Spitzer Light Curves
- Directly Imaged L-T Transition Exoplanets in the Mid-Infrared
- Brown Dwarf Photospheres are Patchy: A Hubble Space Telescope Near-infrared Spectroscopic Survey Finds Frequent Low-level Variability
- The role of convection, overshoot, and gravity waves for the transport of dust in M dwarf and brown dwarf atmospheres
- Atmospheric Dynamics of Hot Giant Planets and Brown Dwarfs
- Spectral evidence for dust in late-type M dwarfs
- Physical and Spectral Characteristics of the T8 and Later-Type Dwarfs
- Fast-evolving weather for the coolest of our two new substellar neighbours
- Atmospheric mass loss by stellar wind from planets around main sequence M stars
- : Pressure-dependent Changes In Light Curve Phase In Brown Dwarfs From Simultaneous and Observations
- A Misaligned Prograde Orbit for Kepler-13 Ab via Doppler Tomography
- Weather on the Nearest Brown Dwarfs: Resolved Simultaneous Multi-Wavelength Variability Monitoring of WISE J104915.57-531906.1AB
- The Onset of Methane in L Dwarfs
- Resolved Near-Infrared Spectroscopy of WISE J104915.57-531906.1AB: A Flux-Reversal Binary at the L dwarf/T dwarf Transition
- Atmospheric Circulation of Brown Dwarfs: Jets, Vortices, and Time Variability
- Atmospheric Circulation of Brown Dwarfs and Jupiter and Saturn-like Planets: Zonal Jets, Long-term Variability, and QBO-type Oscillations
- Atmospheric circulation of brown dwarfs and directly imaged exoplanets driven by cloud radiative feedback: effects of rotation
- Photometric Variability at the L/T Dwarf Boundary
- K2 Ultracool Dwarfs Survey. III. White Light Flares are Ubiquitous in M6-L0 Dwarfs
- Starspot distributions on fully convective M dwarfs: implications for radial velocity planet searches
- Simultaneous, Multi-Wavelength Variability Characterization of the Free-Floating Planetary Mass Object PSO J318.5-22
- Cloud structure of the nearest brown dwarfs: Spectroscopic variability of Luhman 16AB from the Hubble Space Telescope
- Atmospheric circulation of brown dwarfs and directly imaged exoplanets driven by cloud radiative feedback: global and equatorial dynamics
- Cloud Atlas: Discovery of Patchy Clouds and High-amplitude Rotational Modulations In a Young, Extremely Red L-type Brown Dwarf
- Deep Thermal Infrared Imaging of HR 8799 bcde: New Atmospheric Constraints and Limits on a Fifth Planet
- Spectral Variability of VHS J1256-1257 b from 1 to 5 m
- Atmospheric variability driven by radiative cloud feedback in brown dwarfs and directly imaged extrasolar giant planets
- Surprisingly different starspot distributions on the near equal-mass equal-rotation-rate stars in the M dwarf binary GJ 65 AB
- A Monitoring Campaign for Luhman 16AB. I. Detection of Resolved Near-Infrared Spectroscopic Variability
- Characterization of the Nearby L/T Binary Brown Dwarf WISE J104915.57-531906.1 at 2 Parsecs from the Sun
- TESS Observations of the Luhman 16AB Brown Dwarf System: Rotational Periods, Lightcurve Evolution, and Zonal Circulation
- Maps of Evolving Cloud Structures in Luhman 16AB from HST Time-Resolved Spectroscopy
- Cloud Structure of the Nearest Brown Dwarfs II: High-amplitude variability for Luhman 16 A and B in and out of the 0.99 micron FeH feature
- Giant white-light flares on fully convective stars occur at high latitudes
- On the Chemical Abundance of HR 8799 and the Planet c
- Cloud Atlas: Hubble Space Telescope Near-Infrared Spectral Library of Brown Dwarfs, Planetary-mass companions, and hot Jupiters
- Cloud Atlas: Rotational Spectral Modulations and potential Sulfide Clouds in the Planetary-mass, Late T-type Companion Ross 458C
- Cloud Atlas: Discovery of Rotational Spectral Modulations in a Low-mass, L-type Brown Dwarf Companion to a Star
- Cloud Atlas: Rotational Modulations in the L/T Transition Brown Dwarf Companion HN Peg B
- Cloud Atlas: High-Contrast Time-Resolved Observations of Planetary-Mass Companions
- Detection of new strongly variable brown dwarfs in the L/T transition
- Cloud Atlas: Weak color modulations due to rotation in the planetary-mass companion GU Psc b and 11 other brown dwarfs
- Jet Streams and Tracer Mixing in the Atmospheres of Brown Dwarfs and Isolated Young Giant Planets
- Ultracool Dwarfs Survey. VI. White light superflares observed on an L5 dwarf and flare rates of L dwarfs
- Cloud Atlas: Variability in and out of the Water Band in the Planetary-mass HD 203030B Points to Cloud Sedimentation in Low-gravity L Dwarfs
- Individual, Model-Independent Masses of the Closest Known Brown Dwarf Binary to the Sun
- Hubble Space Telescope astrometry of the closest brown dwarf binary system -- I. Overview and improved orbit
- The T Tauri star V410 Tau in the eyes of SPIRou and TESS
- Cloud Atlas: High-precision HST/WFC3/IR Time-Resolved Observations of Directly-Imaged Exoplanet HD106906b
- Cloud Atlas: Unraveling the vertical cloud structure with the time-series spectrophotometry of an unusually red brown dwarf
- KELT-9 as an eclipsing double-lined spectroscopic binary: a unique and self-consistent solution to the system
- Scaling K2. III. Comparable Planet Occurrence in the FGK Samples of Campaign 5 and Kepler
- Cloud-convection feedback in brown dwarfs atmosphere
- Revealing the Vertical Cloud Structure of a young low-mass Brown Dwarf, an analog to the beta-Pictoris b directly-imaged exoplanet, through Keck I/MOSFIRE spectro-photometric variability
- Magnetic field and activity phenomena of the K2 dwarf V471 Tau
- EPIC 203868608: A low-mass quadruple star system in the Upper Scorpius OB association
- Spectral Variability of Two Rapidly Rotating Brown Dwarfs: 2MASS J08354256-0819237 and 2MASS J18212815+1414010
- Time-Resolved High Spectral Resolution Observation of 2MASSW J0746425+200032AB
- Weather on Other Worlds. VI. Optical Spectrophotometry of Luhman 16B Reveals Large-amplitude Variations in the Alkali Lines
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- Roaring Storms in the Planetary-Mass Companion VHS 1256-1257 b: Hubble Space Telescope Multi-epoch Monitoring Reveals Vigorous Evolution in an Ultra-cool Atmosphere
- Measuring the variability of directly imaged exoplanets using vector Apodizing Phase Plates combined with ground-based differential spectrophotometry
- Global weather map reveals persistent top-of-atmosphere features on the nearest brown dwarfs
- Mapping the Skies of Ultracool Worlds: Detecting Storms and Spots with Extremely Large Telescopes
- Mapping atmospheric features of the planetary-mass brown dwarf SIMP 0136 with JWST NIRISS