The Extremely Red, Young L Dwarf PSO J318-22: A Free-Floating Planetary-Mass Analog to Directly Imaged Young Gas-Giant Planets

Abstract

We have used Pan-STARRS1 to discover an extremely red late-L dwarf, which has (J-K)_MKO = 2.84 and (J-K)_2MASS = 2.78, making it the reddest known field dwarf and second only to 2MASS J1207-39b among substellar companions. Near-IR spectroscopy shows a spectral type of L7 and reveals a triangular H-band continuum and weak alkali (K I and Na I) lines, hallmarks of low surface gravity. Near-IR astrometry from the Hawaii Infrared Parallax Program gives a distance of 24.6+/-1.4 pc and indicates a much fainter J-band absolute magnitude than field L dwarfs. The position and kinematics of PSO J318-22 point to membership in the beta Pictoris moving group. Evolutionary models give a temperature of 1160 (-40,+30) K and a mass of 6.5 (-1.0, +1.3) Mjup, making PSO J318-22 one of the lowest mass free-floating objects in the solar neighborhood. This object adds to the growing list of low-gravity field L dwarfs and is the first to be strongly deficient in methane relative to its estimated temperature. Comparing their spectra suggests that young L dwarfs with similar ages and temperatures can have different spectral signatures of youth. For the two objects with well constrained ages (PSO J318-22 and 2MASS J0355+11), we find their temperatures are ~400 K cooler than field objects of similar spectral type but their luminosities are comparable, i.e., these young L dwarfs are very red and unusually cool but not "underluminous." Altogether, PSO J318-22 is the first free-floating object with the colors, magnitudes, spectrum, luminosity, and mass that overlap the young dusty planets around HR 8799 and 2MASS J1207-39.

ApJ Letters, in press. Version 2 incorporates tiny cosmetic changes to match final published version, including a revised Figure 1 that uses the most recent AB Pic b photometry from Biller et al (2013)

References in corpus (10)

• Direct Imaging of Multiple Planets Orbiting the Star HR 8799
• The Evolution of L and T Dwarfs in Color-Magnitude Diagrams
• The 0.8-14.5 micron Spectra of Mid-L to Mid-T Dwarfs: Diagnostics of Effective Temperature, Grain Sedimentation, Gas Transport, and Surface Gravity
• A Near-Infrared Spectroscopic Study of Young Field Ultracool Dwarfs
• Direct Imaging of a Cold Jovian Exoplanet in Orbit around the Sun-like Star GJ 504
• A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages
• Discovery of Two Nearby, Peculiar L Dwarfs from the 2MASS Proper Motion Survey: Young or Metal-Rich?
• Planets Around Low-Mass Stars (PALMS). III. A Young Dusty L Dwarf Companion at the Deuterium-Burning Limit
• Keck Laser Guide Star Adaptive Optics Monitoring of 2MASS J1534-2952AB: First Dynamical Mass Determination of a Binary T Dwarf
• Finding benchmark brown dwarfs to probe the IMF as a function of time

Cited by in corpus (187)

• ATLAS: A High-Cadence All-Sky Survey System
• Euclid. I. Overview of the Euclid mission
• BANYAN. XI. The BANYAN $\Sigma$ multivariate Bayesian algorithm to identify members of young associations within 150 pc
• Imaging Extrasolar Giant Planets
• Fundamental Parameters and Spectral Energy Distributions of Young and Field Age Objects with Masses Spanning the Stellar to Planetary Regime
• No large population of unbound or wide-orbit Jupiter-mass planets
• BANYAN. II. Very Low Mass and Substellar Candidate Members to Nearby, Young Kinematic Groups With Previously Known Signs of Youth
• Population Properties of Brown Dwarf Analogs to Exoplanets
• The Hawaii Infrared Parallax Program. II. Young Ultracool Field Dwarfs
• BANYAN. VII. A New Population of Young Substellar Candidate Members of Nearby Moving Groups from the BASS Survey
• Retrieving scattering clouds and disequilibrium chemistry in the atmosphere of HR 8799e
• Discovery of a warm, dusty giant planet around HIP65426
• Individual Dynamical Masses of Ultracool Dwarfs
• Water Clouds in Y Dwarfs and Exoplanets
• The Field Substellar Mass Function Based on the Full-sky 20-pc Census of 525 L, T, and Y Dwarfs
• Discovery of a young planetary mass companion to the nearby M dwarf VHS J125601.92-125723.9
• The UKIRT Hemisphere Survey: Definition and J-band Data Release
• First light of the VLT planet finder SPHERE. IV. Physical and chemical properties of the planets around HR8799
• Directly Imaged L-T Transition Exoplanets in the Mid-Infrared
• Preliminary Trigonometric Parallaxes of 184 Late-T and Y Dwarfs and an Analysis of the Field Substellar Mass Function into the "Planetary" Mass Regime
• Photometry and Proper Motions of M, L, and T Dwarfs from the Pan-STARRS1 3$\pi$ Survey
• Characterizing 51 Eri b from 1-5 $\mu$m: a partly-cloudy exoplanet
• The VLT/NaCo large program to probe the occurrence of exoplanets and brown dwarfs at wide orbits: II- Survey description, results and performances
• BANYAN. V. A Systematic All-Sky Survey for New Very Late-Type Low-Mass Stars and Brown Dwarfs in Nearby Young Moving Groups
• Disk evolution, element abundances and cloud properties of young gas giant planets
• All-sky Co-moving Recovery Of Nearby Young Members. (ACRONYM) II: The Beta Pictoris Moving Group
• A Volume-Limited Sample of Ultracool Dwarfs. I. Construction, Space Density, and a Gap in the L/T Transition
• Cloud busting: enstatite and quartz clouds in the atmosphere of 2M2224-0158
• A rich population of free-floating planets in the Upper Scorpius young stellar association
• The Viewing Geometry of Brown Dwarfs Influences Their Observed Colours and Variability Properties
• Atmospheric Regimes and Trends on Exoplanets and Brown Dwarfs
• A Survey for New Members of the Taurus Star-Forming Region with the Sloan Digital Sky Survey
• LACEwING: A New Moving Group Analysis Code
• Spectroscopic Confirmation of Young Planetary-Mass Companions on Wide Orbits
• A Search for L/T Transition Dwarfs With Pan-STARRS1 and WISE. II. L/T Transition Atmospheres and Young Discoveries
• A Survey for New Members of Taurus from Stellar to Planetary Masses
• Spectroscopic characterization of HD 95086 b with the Gemini Planet Imager
• Near-infrared photometry of Y dwarfs: low ammonia abundance and the onset of water clouds
• Keck/NIRC2 $L$'-Band Imaging of Jovian-Mass Accreting Protoplanets around PDS 70
• BANYAN. IX. The Initial Mass Function and Planetary-Mass Object Space Density of the TW Hya Association
• The GJ 504 system revisited. Combining interferometric, radial velocity, and high contrast imaging data
• Spectral Variability from the Patchy Atmospheres of T and Y Dwarfs
• Direct Imaging and Astrometric Detection of a Gas Giant Planet Orbiting an Accelerating Star
• Variability in a Young, L/T Transition Planetary-Mass Object
• SDSS J111010.01+011613.1: A New Planetary-Mass T Dwarf Member of the AB Doradus Moving Group
• Simultaneous, Multi-Wavelength Variability Characterization of the Free-Floating Planetary Mass Object PSO J318.5-22
• Discovery of a Substellar Companion to the Nearby Debris Disk Host HR 2562
• SIMP J013656.5+093347 is Likely a Planetary-Mass Object in the Carina-Near Moving Group
• Survivability of planetary systems in young and dense star clusters
• SPHERE/SHINE reveals concentric rings in the debris disk of HIP 73145
• WISEP J004701.06+680352.1: An intermediate surface gravity, dusty brown dwarf in the AB Dor Moving Group
• The LEECH Exoplanet Imaging Survey: Characterization of the Coldest Directly Imaged Exoplanet, GJ 504 b, and Evidence for Super-Stellar Metallicity
• Cloud Atlas: Discovery of Patchy Clouds and High-amplitude Rotational Modulations In a Young, Extremely Red L-type Brown Dwarf
• In-depth study of moderately young but extremely red, very dusty substellar companion HD206893B
• Thermo-compositional diabatic convection in the atmospheres of brown dwarfs and in Earth's atmosphere and oceans
• Search for free-floating planetary-mass objects in the Pleiades
• Spitzer Variability Properties of Low-Gravity L Dwarfs
• WISEA J114724.10-204021.3: A Free-Floating Planetary Mass Member of the TW Hya Association
• The extremely red L dwarf ULAS J222711$-$004547 - dominated by dust
• Spectral Variability of VHS J1256-1257 b from 1 to 5 $\mu$m
• BANYAN. XII. New Members of Nearby Young Associations from Gaia-Tycho Data
• Physical and orbital properties of Beta Pictoris b
• Trigonometric parallaxes of young field L dwarfs
• The Young L Dwarf 2MASS J11193254-1137466 is a Planetary-Mass Binary
• Variability of the Lowest Mass Objects in the AB Doradus Moving Group
• Photometric brown-dwarf classification. II. A homogeneous sample of 1361 L and T dwarfs brighter than J = 17.5 with accurate spectral types
• A Targeted Search for Peculiarly Red L and T Dwarfs in SDSS, 2MASS, and WISE: Discovery of a Possible L7 Member of the TW Hydrae Association
• Cloudless atmospheres for young low-gravity substellar objects
• Exploring the Role of Sub-micron Sized Dust Grains in the Atmospheres of Red L0 - L6 Dwarfs
• The optical+infrared L dwarf spectral sequence of young planetary-mass objects in the Upper Scorpius association
• Spitzer and z' Secondary Eclipse Observations of the Highly Irradiated Transiting Brown Dwarf KELT-1b
• Adaptive Optics imaging of VHS 1256-1257: A Low Mass Companion to a Brown Dwarf Binary System
• A Number of Nearby Moving Groups may be Fragments of Dissolving Open Clusters
• Spectroscopic confirmation of M-dwarf candidate members of the Beta Pictoris and AB Doradus Moving Groups
• A 2MASS/AllWISE Search for Extremely Red L Dwarfs -- The Discovery of Several Likely L Type Members of $\beta$ Pic, AB Dor, Tuc-Hor, Argus, and the Hyades
• Photometric brown-dwarf classification. I. A method to identify and accurately classify large samples of brown dwarfs without spectroscopy
• Planets Around Low-Mass Stars (PALMS). VI. Discovery of a Remarkably Red Planetary-Mass Companion to the AB Dor Moving Group Candidate 2MASS J22362452+4751425
• Simultaneous Multiwavelength Observations of Magnetic Activity in Ultracool Dwarfs. IV. The Active, Young Binary NLTT 33370 AB (=2MASS J13142039+1320011)
• Brown Dwarfs in Young Moving Groups from Pan-STARRS1. I. AB Doradus
• The Radial and Rotational Velocities of PSO J318.5338$-$22.8603, a Newly Confirmed Planetary-Mass Member of the $\beta$ Pictoris Moving Group
• Indications of Water Clouds in the Coldest Known Brown Dwarf
• The Demographics of Rocky Free-Floating Planets and their Detectability by WFIRST
• The Coolest Isolated Brown Dwarf Candidate Member of TWA
• New constraints on the formation and settling of dust in the atmospheres of young M and L dwarfs
• The Hawaii Infrared Parallax Program. V. New T-Dwarf Members and Candidate Members of Nearby Young Moving Groups
• COol Companions ON Ultrawide orbiTS (COCONUTS). I. A High-Gravity T4 Benchmark around an Old White Dwarf and A Re-Examination of the Surface-Gravity Dependence of the L/T Transition
• The Mass-Luminosity Relation in the L/T Transition: Individual Dynamical Masses for the New J-Band Flux Reversal Binary SDSSJ105213.51+442255.7AB
• Brown dwarf census with the Dark Energy Survey year 3 data and the thin disk scale height of early L types
• The Elusive Majority of Young Moving Groups. I. Young Binaries and Lithium-Rich Stars in the Solar Neighborhood
• Survival Rates of Planets in Open Clusters: the Pleiades, Hyades, and Praesepe clusters
• JWST/NIRSpec Observations of the Planetary Mass Companion TWA 27B
• 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
• The Nearest Isolated Member of the TW Hydrae Association is a Giant Planet Analog
• Cloud Atlas: Hubble Space Telescope Near-Infrared Spectral Library of Brown Dwarfs, Planetary-mass companions, and hot Jupiters
• The Pan-Pacific Planet Search VII: The most eccentric planet orbiting a giant star
• Discovery of a new Y dwarf: WISE J030449.03-270508.3
• On the Detection of Exomoons Transiting Isolated Planetary-Mass Objects
• The B-Star Exoplanet Abundance Study: a co-moving 16-25 Mjup companion to the young binary system HIP 79098
• A High-Contrast Search for Variability in HR 8799bc with VLT-SPHERE
• BANYAN. VIII. New Low-Mass Stars and Brown Dwarfs with Candidate Circumstellar Disks
• Retrieval study of cool, directly imaged exoplanet 51 Eri b
• A Search for L/T Transition Dwarfs With Pan-STARRS1 and WISE. III. Young L Dwarf Discoveries and Proper Motion Catalogs in Taurus and Scorpius-Centaurus
• Methane in Analogs of Young Directly Imaged Exoplanets
• Planets Around Low-Mass Stars (PALMS). V. Age-Dating Low-Mass Companions to Members and Interlopers of Young Moving Groups
• 2MASS J13243553+6358281 is an Early T-Type Planetary-Mass Object in the AB Doradus Moving Group
• Addressing Systematics in the Traceback Age of the $\beta$ Pictoris Moving Group
• Can the masses of isolated planetary-mass gravitational lenses be measured by terrestrial parallax?
• WISE2150-7520AB: A very low mass, wide co-moving brown dwarf system discovered through the citizen science project Backyard Worlds: Planet 9
• A Reanalysis of the Fundamental Parameters and Age of TRAPPIST-1
• Optical and Near-Infrared Spectra of sigma Orionis Isolated Planetary-mass Objects
• Dynamical Mass Measurement of the Young Spectroscopic Binary V343 Normae AaAb Resolved With the Gemini Planet Imager
• Detection of new strongly variable brown dwarfs in the L/T transition
• Characterizing HR3549B using SPHERE
• Early Results from VLT-SPHERE: Long-Slit Spectroscopy of 2MASS 0122-2439B, a Young Companion Near the Deuterium Burning Limit
• Gemini Planet Imager Spectroscopy of the Dusty Substellar Companion HD 206893 B
• 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
• Orbital and spectral characterization of the benchmark T-type brown dwarf HD 19467B
• Occurrence Rates from Direct Imaging Surveys
• The origin of free-floating planets
• Infrared Spectroscopy of free-floating planet candidates in Upper Scorpius and Ophiuchus
• A dusty benchmark brown dwarf near the ice line of HD 72946
• Presence of water on exomoons orbiting free-floating planets: a case study
• On the Feasibility of Characterizing Free-floating Planets with Current and Future Space-based Microlensing Surveys
• Spectral library of age-benchmark low-mass stars and brown dwarfs
• A Novel Survey for Young Substellar Objects with the W-band filter II. The Coolest and Lowest Mass Members of the Serpens-South Star-forming Region
• Spectroscopic follow-up of L- and T-type proper-motion member candidates in the Pleiades
• Could Jupiter or Saturn Have Ejected a Fifth Giant Planet?
• The Oceanus Moving Group: A New 500 Myr-Old Host for the Nearest Brown Dwarf
• A Wide Planetary Mass Companion Discovered Through the Citizen Science Project Backyard Worlds: Planet 9
• Evidence for SiO cloud nucleation in the rogue planet PSO J318
• Cloud Atlas: High-precision HST/WFC3/IR Time-Resolved Observations of Directly-Imaged Exoplanet HD106906b
• A wide planetary-mass companion to a young low-mass brown dwarf in Ophiuchus
• The Prototypical Young L/T-Transition Dwarf HD 203030B Likely Has Planetary Mass
• Redder than Red: Discovery of an Exceptionally Red L/T Transition Dwarf
• Optical and near-infrared linear polarization of low and intermediate-gravity ultra-cool dwarfs
• Orbiting a binary: SPHERE characterisation of the HD 284149 system
• WEIRD: Wide-orbit Exoplanet search with InfraRed Direct imaging
• A Census of the 32 Ori Association with Gaia
• Spitzer Light Curves of the Young, Planetary-Mass TW Hya Members 2MASS J11193254-1137466AB and WISEA J114724.10-204021.3
• On the detection of free-floating planets through microlensing towards the Magellanic Clouds
• A Near-infrared Variability Survey of Young Planetary-mass Objects
• New spectro-photometric characterization of the substellar object HR 2562 B using SPHERE
• Spectral energy distribution simulations of a possible ring structure around the young, red brown dwarf G196-3B
• Thermal Infrared Imaging and Atmospheric Modeling of VHS J125601.92-125723.9 b: Evidence for Moderately Thick Clouds and Equilibrium Carbon Chemistry in a Hierarchical Triple System
• Understanding Fundamental Properties and Atmospheric Features of Subdwarfs via a Case Study of SDSS J125637.13-022452.4
• Dynamical Mass of the Young Brown Dwarf Companion PZ Tel B
• Exploring the planetary-mass population in the Upper Scorpius association
• Prospects for Directly Imaging Young Giant Planets at Optical Wavelengths
• A LOFAR mini-survey for low-frequency radio emission from the nearest brown dwarfs
• 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
• L-band Spectroscopy with Magellan-AO/Clio2: First Results on Young Low-Mass Companions
• New Candidates for Planetary-mass Brown Dwarfs in IC 348
• MaB$\mu$lS-2: high-precision microlensing modelling for the large-scale survey era
• Radio emission in a nearby ultracool dwarf binary: a multi-frequency study
• The puzzle of the formation of T8 dwarf Ross 458c
• Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30
• A New Method for Characterizing Very-Low-Mass Companions with Low Resolution Near-Infrared Spectroscopy
• Microlensing due to free-floating moon-planet systems
• Radial Velocities, Space Motions, and Nearby Young Moving Group Memberships of Eleven Candidate Young Brown Dwarfs
• CWISE J014611.20-050850.0AB: The Widest Known Brown Dwarf Binary in the Field
• The ESO SupJup Survey VIII. Chemical fingerprints of young L dwarf twins
• Spectral characterization of young LT dwarfs
• CFBDSIR 2149-0403: young isolated planetary-mass object or high-metallicity low-mass brown dwarf??
• Population synthesis of exoplanets accounting for orbital variations due to stellar evolution
• Detecting free-floating planets using water-depend colour terms in the next generation of infrared space-based surveys
• COol Companions ON Ultrawide orbiTS (COCONUTS). III. A Very Red L6 Benchmark Brown Dwarf around a Young M5 Dwarf
• Presence of liquid water during the evolution of exomoons orbiting ejected free-floating planets
• Confirming the least massive members of the Pleiades star cluster
• Atmospheric Characterization and Further Orbital Modeling of $\kappa$ And b
• Discovery of Young Methane Dwarfs in the Rho Ophiuchi L 1688 Dark Cloud
• X-SHYNE: X-Shooter spectra of young exoplanet analogs II. Presentation and analysis of the full library
• Exoplanet Atmosphere Measurements from Direct Imaging
• Free-floating planetary mass objects in LDN 1495 from Euclid Early Release Observations
• $L$-band Spectra of Young Brown Dwarfs
• An optimised survey strategy for the ERIS/NIX imager: searching for young giant exoplanets and very low mass brown dwarfs using the K-peak custom photometric filter
• Large Scale Searches for Brown Dwarfs and Free-Floating Planets
• The planetary-mass-limit VLT/SINFONI library: Spectral extraction and atmospheric characterization via forward modeling
• Probing Superheavy Dark Matter with Exoplanets
• Planetary Systems in a Star Cluster II: intermediate-mass black holes and planetary systems
• Using Source Proper Motion to Validate Terrestrial Parallax: OGLE-2019-BLG-1058
• Simulation of images of protoplanetary disks after collision with free-floating planets
• Direct Imaging Discovery of Giant Exoplanet $\beta$ Pictoris d: A Decade-Long Game of Hide-and-Seek
• Using Old and New Approaches: Determining Physical Properties of Brown Dwarfs with Empirical Relations and Machine Learning Models
• SCExAO/CHARIS Multi-Wavelength, High-Contrast Imaging of the BD+45${}^{\circ }$598 Debris Disk
• Ross 19B: An Extremely Cold Companion Discovered via the Backyard Worlds: Planet 9 Citizen Science Project
• Life in the dark: Potential urability of moons of rogue planets
• Disentangling the Signatures of Blended-Light Atmospheres in L/T Transition Brown Dwarfs