On the Detection of Exomoons Transiting Isolated Planetary-Mass Objects

Abstract

All-sky imaging surveys have identified several dozen isolated planetary-mass objects (IPMOs), far away from any star. Here, we examine the prospects for detecting transiting moons around these objects. We expect transiting moons to be common, occurring around 10-15% of IPMOs, given that close-orbiting moons have a high geometric transit probability and are expected to be a common outcome of giant planet formation. IPMOs offer an advantage over other directly imaged planets in that high-contrast imaging is not necessary to detect the photometric transit signal. For at least 30 (>50%) of the currently known IPMOs, observations of a single transit with the James Webb Space Telescope would have low enough forecasted noise levels to allow for the detection of an Io-like or Titan-like moon. Intrinsic variability of the IPMOs will be an obstacle. Using archival time-series photometry of IPMOs with the Spitzer Space Telescope as a proof-of-concept, we found evidence for a fading event of 2MASS J1119-1137 AB that might have been caused by intrinsic variability, but is also consistent with a single transit of a habitable-zone 1.7$R_{\oplus }$ exomoon. Although the interpretation of this particular event is inconclusive, the characteristics of the data and the candidate signal suggest that Earth-sized habitable-zone exomoons around IPMOs are detectable with existing instrumentation.

arXiv commentAccepted to ApJ Letters

References in corpus (135)

• emcee: The MCMC Hammer
• The NumPy array: a structure for efficient numerical computation
• The Transiting Exoplanet Survey Satellite
• dynesty: A Dynamic Nested Sampling Package for Estimating Bayesian Posteriors and Evidences
• Habitable Zones Around Main-Sequence Stars: New Estimates
• New evolutionary models for pre-main sequence and main sequence low-mass stars down to the hydrogen-burning limit
• The California-Kepler Survey. III. A Gap in the Radius Distribution of Small Planets
• Planetary Radii across Five Orders of Magnitude in Mass and Stellar Insolation: Application to Transits
• A giant planet imaged in the disk of the young star Beta Pictoris
• The evaporation valley in the Kepler planets
• Understanding the Mass-Radius Relation for Sub-Neptunes: Radius as a Proxy for Composition
• The Evolution of L and T Dwarfs in Color-Magnitude Diagrams
• A probable giant planet imaged in the Beta Pictoris disk
• The Hawaii Infrared Parallax Program. I. Ultracool Binaries and the L/T Transition
• Design Considerations for a Ground-based Transit Search for Habitable Planets Orbiting M dwarfs
• The First Hundred Brown Dwarfs Discovered by the Wide-field Infrared Survey Explorer (WISE)
• The Discovery of Y Dwarfs Using Data from the Wide-field Infrared Survey Explorer (WISE)
• Imaging Extrasolar Giant Planets
• Further Defining Spectral Type "Y" and Exploring the Low-mass End of the Field Brown Dwarf Mass Function
• Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime
• Dearth of short-period Neptunian exoplanets - a desert in period-mass and period-radius planes
• The Frequency of Hot Jupiters Orbiting Nearby Solar-Type Stars
• STARRY: Analytic Occultation Light Curves
• The Deuterium-Burning Mass Limit for Brown Dwarfs and Giant Planets
• Weather on Other Worlds. II. Survey Results: Spots Are Ubiquitous on L and T Dwarfs
• Formation and Structure of Low Density Exo-Neptunes
• Characterization of exoplanets from their formation II: The planetary mass-radius relationship
• Population Properties of Brown Dwarf Analogs to Exoplanets
• A Circumplanetary Disk Around PDS70c
• A Study of the Shortest-Period Planets Found With Kepler
• The Hawaii Infrared Parallax Program. II. Young Ultracool Field Dwarfs
• HST Spectral Mapping of L/T Transition Brown Dwarfs Reveals Cloud Thickness Variations
• The Extremely Red, Young L Dwarf PSO J318-22: A Free-Floating Planetary-Mass Analog to Directly Imaged Young Gas-Giant Planets
• Distances, Luminosities, and Temperatures of the Coldest Known Substellar Objects
• Large Amplitude Variations of an L/T Transition Brown Dwarf: Multi-Wavelength Observations of Patchy, High-Contrast Cloud Features
• Strong Brightness Variations Signal Cloudy-to-Clear Transition of Brown Dwarfs
• Discovery of a ~250 K Brown Dwarf at 2 pc from the Sun
• Discovery of a Candidate for the Coolest Known Brown Dwarf
• Emerging Trends in a Period-Radius Distribution of Close-in Planets
• A Sub-Earth-Mass Moon Orbiting a Gas Giant Primary or a High Velocity Planetary System in the Galactic Bulge
• Evidence for a Large Exomoon Orbiting Kepler-1625b
• The Planetary Mass Companion 2MASS1207-3932 B: Temperature, Mass and Evidence for an Edge-On Disk
• The Field Substellar Mass Function Based on the Full-sky 20-pc Census of 525 L, T, and Y Dwarfs
• 2MASSJ035523.51+113337.4: A Young, Dusty, Nearby, Isolated Brown Dwarf Resembling A Giant Exoplanet
• Origin of the Different Architectures of the Jovian and Saturnian Satellite Systems
• HD 203030B: an Unusually Cool Young Sub-Stellar Companion near the L/T Transition
• Brown Dwarf Photospheres are Patchy: A Hubble Space Telescope Near-infrared Spectroscopic Survey Finds Frequent Low-level Variability
• The Roche limit for close-orbiting planets: Minimum density, composition constraints, and application to the 4.2-hour planet KOI 1843.03
• Formation, Habitability, and Detection of Extrasolar Moons
• Photometry and Proper Motions of M, L, and T Dwarfs from the Pan-STARRS1 3$\pi$ Survey
• The scatter of the M dwarf mass-radius relationship
• Modeling giant extrasolar ring systems in eclipse and the case of J1407b: sculpting by exomoons?
• Two new HATNet hot Jupiters around A stars, and the first glimpse at the occurrence rate of hot Jupiters from TESS
• HEK VI: On the Dearth of Galilean Analogs in Kepler and the Exomoon Candidate Kepler-1625b I
• Hubble Space Telescope Spectroscopy of Brown Dwarfs Discovered with the Wide-field Infrared Survey Explorer
• N-body Simulations of Satellite Formation around Giant Planets: Origin of Orbital Configuration of the Galilean Moons
• A Volume-Limited Sample of Ultracool Dwarfs. I. Construction, Space Density, and a Gap in the L/T Transition
• Discovery of the Young L Dwarf WISE J1741102.78-464225.5
• The Viewing Geometry of Brown Dwarfs Influences Their Observed Colours and Variability Properties
• Discovery of Rotational Modulations in the Planetary-Mass Companion 2M1207b: Intermediate Rotation Period and Heterogeneous Clouds in a Low Gravity Atmosphere
• Detecting companions to extrasolar planets using mutual events
• The Y-Type Brown Dwarfs: Estimates of Mass and Age from New Astrometry, Homogenized Photometry and Near-Infrared Spectroscopy
• The properties of the T8.5p dwarf Ross 458C
• Hip 63510C, Hip 73786B, and nine new isolated high proper motion T dwarf candidates from UKIDSS DR6 and SDSS DR7
• A new benchmark T8-9 brown dwarf and a couple of new mid-T dwarfs from the UKIDSS DR5+ LAS
• High-Cadence, High-Contrast Imaging for Exoplanet Mapping: Observations of the HR 8799 Planets with VLT/SPHERE Satellite Spot-Corrected Relative Photometry
• Escape of the martian protoatmosphere and initial water inventory
• No Evidence for Lunar Transit in New Analysis of Hubble Space Telescope Observations of the Kepler-1625 System
• SDSS J111010.01+011613.1: A New Planetary-Mass T Dwarf Member of the AB Doradus Moving Group
• The Hawaii Infrared Parallax Program. IV. A Comprehensive Parallax Survey of L0-T8 dwarfs with UKIRT
• Simultaneous, Multi-Wavelength Variability Characterization of the Free-Floating Planetary Mass Object PSO J318.5-22
• SIMP J013656.5+093347 is Likely a Planetary-Mass Object in the Carina-Near Moving Group
• Atmospheric circulation of brown dwarfs and directly imaged exoplanets driven by cloud radiative feedback: global and equatorial dynamics
• On the detection of Exomoons: A search in Kepler data for the orbital sampling effect and the scatter peak
• Confirmation of One of the Coldest Known Brown Dwarfs
• Spitzer Variability Properties of Low-Gravity L Dwarfs
• Sodium and Potassium Signatures of Volcanic Satellites Orbiting Close-in Gas Giant Exoplanets
• WISEA J114724.10-204021.3: A Free-Floating Planetary Mass Member of the TW Hya Association
• Spectral Variability of VHS J1256-1257 b from 1 to 5 $\mu$m
• The Center of Light: Spectroastrometric Detection of Exomoons
• Hydrodynamic simulations of captured protoatmospheres around Earth-like planets
• The First Detection of Photometric Variability in a Y Dwarf: WISE J140518.39+553421.3
• Runaway greenhouse effect on exomoons due to irradiation from hot, young giant planets
• A Search for Variability in Exoplanet Analogues and Low-Gravity Brown Dwarfs
• Variability of the Lowest Mass Objects in the AB Doradus Moving Group
• The Young L Dwarf 2MASS J11193254-1137466 is a Planetary-Mass Binary
• Ground-based K-band detection of thermal emission from the exoplanet TrES-3b
• Strong Near-Infrared Spectral Variability of the Young Cloudy L Dwarf Companion VHS J1256-1257 b
• Transit Probabilities for Stars With Stellar Inclination Constraints
• Transit of Exomoon Plasma Tori: New Diagnosis
• Formation of moon systems around giant planets: Capture and ablation of planetesimals as foundation for a pebble accretion scenario
• To cool is to keep: Residual H/He atmospheres of super-Earths and sub-Neptunes
• Alkaline Exospheres of Exoplanet Systems: Evaporative Transmission Spectra
• TESS Observations of the Luhman 16AB Brown Dwarf System: Rotational Periods, Lightcurve Evolution, and Zonal Circulation
• Recent Transits of the Super-Earth Exoplanet GJ 1214b
• Constraining the entropy of formation from young transiting planets
• Observed Variability at 1um and 4um in the Y0 Brown Dwarf WISEP J173835.52+273258.9
• The Hawaii Infrared Parallax Program. V. New T-Dwarf Members and Candidate Members of Nearby Young Moving Groups
• The Hawaii Infrared Parallax Program. III. 2MASS J0249-0557 c: A Wide Planetary-mass Companion to a Low-mass Binary in the beta Pic Moving Group
• HD 89345: a bright oscillating star hosting a transiting warm Saturn-sized planet observed by K2
• Sensitivity of Transit Searches to Habitable Planets
• Revisiting the exomoon candidate signal around Kepler-1625b
• Detecting Exomoons Via Doppler Monitoring of Directly Imaged Exoplanets
• Cloud Atlas: Hubble Space Telescope Near-Infrared Spectral Library of Brown Dwarfs, Planetary-mass companions, and hot Jupiters
• Exomoon Candidates from Transit Timing Variations: Eight Kepler systems with TTVs explainable by photometrically unseen exomoons
• Photometric Monitoring of the Coldest Known Brown Dwarf with the Spitzer Space Telescope
• The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog
• Cloud Atlas: Rotational Spectral Modulations and potential Sulfide Clouds in the Planetary-mass, Late T-type Companion Ross 458C
• Innocent Bystanders: Orbital Dynamics of Exomoons during Planet-Planet Scattering
• Conditions for water ice lines and Mars-mass exomoons around accreting super-Jovian planets at 1 - 20 AU from Sun-like stars
• Brown Dwarf Binaries from Disintegrating Triple Systems
• A High-Contrast Search for Variability in HR 8799bc with VLT-SPHERE
• A semi-analytical model for exploring Galilean satellites formation from a massive disk
• WISEA J083011.95+283716.0: A Missing Link Planetary-Mass Object
• 2MASS J13243553+6358281 is an Early T-Type Planetary-Mass Object in the AB Doradus Moving Group
• A search for multi-planet systems with TESS using a Bayesian N-body retrieval and machine learning
• Loose Ends for the Exomoon Candidate Host Kepler-1625b
• Satellites Form Fast & Late: a Population Synthesis for the Galilean Moons
• Cloud Atlas: Weak color modulations due to rotation in the planetary-mass companion GU Psc b and 11 other brown dwarfs
• Spin-orbit alignment of the $\beta$ Pictoris planetary system
• An N-body population synthesis framework for the formation of moons around Jupiter-like planets
• Rotational Light Curves of Jupiter from UV to Mid-Infrared and Implications for Brown Dwarfs and Exoplanets
• The search for disks or planetary objects around directly imaged companions: A candidate around DH Tau B
• Formation of satellites in circumplanetary discs generated by disc instability
• A Transient Transit Signature Associated with the Young Star RIK-210
• MOA-2015-BLG-337: A Planetary System with a Low-mass Brown Dwarf/Planetary Boundary Host, or a Brown Dwarf Binary
• Kepler Monitoring of an L Dwarf II. Clouds with Multiyear Lifetimes
• Presence of water on exomoons orbiting free-floating planets: a case study
• Transits of extrasolar moons around luminous giant planets
• Spitzer Light Curves of the Young, Planetary-Mass TW Hya Members 2MASS J11193254-1137466AB and WISEA J114724.10-204021.3
• A search for photometric variability in the young T3.5 planetary-mass companion GU Psc b
• Growth and evolution of satellites in a Jovian massive disc
• Survivability of Moon Systems Around Ejected Gas Giants
• Design Considerations for a Ground-Based Search for Transiting Planets around L and T Dwarfs
• New Method to Measure Proper Motions of Microlensed Sources: Application to Candidate Free-Floating-Planet Event MOA-2011-BLG-262

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• Resolved imaging of an extrasolar radiation belt around an ultracool dwarf
• A Near-infrared Variability Survey of Young Planetary-mass Objects
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• Predicting the Yield of Small Transiting Exoplanets around Mid-M and Ultra-Cool Dwarfs in the Nancy Grace Roman Space Telescope Galactic Bulge Time Domain Survey
• The TEMPO Survey I: Predicting Yields of the Transiting Exosatellites, Moons, and Planets from a 30-day Survey of Orion with the Nancy Grace Roman Space Telescope
• Measuring the variability of directly imaged exoplanets using vector Apodizing Phase Plates combined with ground-based differential spectrophotometry
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• The Perkins INfrared Exosatellite Survey (PINES) II. Transit Candidates and Implications for Planet Occurrence around L and T Dwarfs
• Exomoon search with VLTI/GRAVITY around the substellar companion HD 206893 B
• Direct detectability of tidally heated exomoons by photometric orbital modulation
• Presence of liquid water during the evolution of exomoons orbiting ejected free-floating planets
• The "Drake equation" of exomoons -- a cascade of formation, stability and detection
• Astrometric exomoon detection by means of optical interferometry
• The Dynamics of Co-orbital Giant Exomoons -- Applications for the Kepler-1625 b and Kepler-1708 b Satellite Systems
• Sensitivity to Sub-Io-sized Exosatellite Transits in the MIRI LRS Lightcurve of the Nearest Substellar Worlds
• Life in the dark: Potential urability of moons of rogue planets