The Wide Brown Dwarf Binary Oph 1622-2405 and Discovery of A Wide, Low Mass Binary in Ophiuchus (Oph 1623-2402): A New Class of Young Evaporating Wide Binaries?

Abstract

We imaged five objects near the star forming clouds of Ophiuchus with the Keck Laser Guide Star AO system. We resolved Allers et al. (2006)'s #11 (Oph 16222-2405) and #16 (Oph 16233-2402) into binary systems. The #11 object is resolved into a 243 AU binary, the widest known for a very low mass (VLM) binary. The binary nature of #11 was discovered first by Allers (2005) and independently here during which we obtained the first spatially resolved R~2000 near-infrared (J & K) spectra, mid-IR photometry, and orbital motion estimates. We estimate for 11A and 11B gravities (log(g)>3.75), ages (5+/-2 Myr), luminosities (log(L/Lsun)=-2.77+/-0.10 and -2.96+/-0.10), and temperatures (Teff=2375+/-175 and 2175+/-175 K). We find self-consistent DUSTY evolutionary model (Chabrier et al. 2000) masses of 17+4-5 MJup and 14+6-5 MJup, for 11A and 11B respectively. Our masses are higher than those previously reported (13-15 MJup and 7-8 MJup) by Jayawardhana & Ivanov (2006b). Hence, we find the system is unlikely a ``planetary mass binary'', (in agreement with Luhman et al. 2007) but it has the second lowest mass and lowest binding energy of any known binary. Oph #11 and Oph #16 belong to a newly recognized population of wide (>100 AU), young (<10 Myr), roughly equal mass, VLM stellar and brown dwarf binaries. We deduce that ~6+/-3% of young (<10 Myr) VLM objects are in such wide systems. However, only 0.3+/-0.1% of old field VLM objects are found in such wide systems. Thus, young, wide, VLM binary populations may be evaporating, due to stellar encounters in their natal clusters, leading to a field population depleted in wide VLM systems.

Accepted version V2. Now 13 pages longer (45 total) due to a new discussion of the stability of the wide brown dwarf binary population, new summary Figure 17 now included, Astrophysical Journal 2007 in press

References in corpus (54)

• Correcting for the Effects of Interstellar Extinction
• Evolutionary models for very-low-mass stars and brown dwarfs with dusty atmospheres
• The Formation of a Star Cluster: Predicting the Properties of Stars and Brown Dwarfs
• A Giant Planet Candidate near a Young Brown Dwarf
• Evolutionary models for low-mass stars and brown dwarfs: uncertainties and limits at very young ages
• From Molecular Cores to Planet-forming Disks: A SIRTF Legacy Program
• New Neighbors from 2MASS: Activity and Kinematics at the Bottom of the Main Sequence
• L' and M' Photometry of Ultracool Dwarfs
• Binarity in Brown Dwarfs: T Dwarf Binaries Discovered with the Hubble Space Telescope WPFC2
• The Formation Mechanism of Brown Dwarfs
• L and T Dwarf Models and the L to T Transition
• Young Low-Mass Stars and Brown Dwarfs in IC 348
• Detection of Nine M8.0-L0.5 Binaries: The Very Low Mass Binary Population and its Implications for Brown Dwarf and VLM Star Formation
• The NIRSPEC Brown Dwarf Spectroscopic Survey. I. Low-Resolution Near-Infrared Spectra
• The local density of matter mapped by Hipparcos
• Multiplicity of Nearby Free-floating Ultra-cool Dwarfs: a HST-WFPC2 search for companions
• A companion to AB Pic at the planet/brown dwarf boundary
• Giant Planet Companion to 2MASSW J1207334-393254
• A Moving Cluster Distance to the Exoplanet 2M1207 B in the TW Hya Association
• Discovery of a Very Young Field L Dwarf, 2MASS J01415823-4633574
• Characterizing Young Brown Dwarfs using Low Resolution Near-IR Spectra
• The Evolution of Binary Fractions in Globular Clusters
• Hubble Space Telescope Observations of Binary Very-Low-Mass Stars and Brown Dwarfs
• The Initial Configuration of Young Stellar Clusters: A K-band Number Counts Analysis of the Surface Density of Stars
• Identifying Young Brown Dwarfs Using Gravity-Sensitive Spectral Features
• Optical Spectroscopy of the Surface Population of the rho Ophiuchi Molecular Cloud: The First Wave of Star Formation
• Gravity Indicators in the Near-Infrared Spectra of Brown Dwarfs
• A search for binary systems among the nearest L dwarfs
• Formation and Evolution of Planetary Systems (FEPS): Primordial Warm Dust Evolution From 3-30 Myr around Sun-like Stars
• Young, Low-Mass Brown Dwarfs with Mid-Infrared Excesses
• Discovery of a Planetary-Mass Brown Dwarf with a Circumstellar Disk
• The First Discovery of a Wide Binary Brown Dwarf
• Constraining the Lifetime of Circumstellar Disks in the Terrestrial Planet Zone: A Mid-IR Survey of the 30-Myr-old Tucana-Horologium Association
• Discovery of Two Very Low-Mass Binaries: Final Results of an Adaptive Optics Survey of Nearby M6.0-M7.5 Stars
• An HST/WFPC2 Survey for Brown Dwarf Binaries in the alpha Per and the Pleiades Open Clusters
• An Adaptive Optics Survey of M8-M9 Stars: Discovery of 4 Very Low mass Binaries With at Least One System Containing a Brown Dwarf Companion
• Deficit of wide binaries in the eta Chamaeleontis young cluster
• Multiplicity and Optical Excess Across the Substellar Boundary in Taurus
• The Minimum Mass for Opacity-Limited Fragmentation in Turbulent Cloud Cores
• Discovery of 9 New Companions to Nearby Young M Stars with the Altair AO System
• HST NICMOS Imaging of the Planetary-mass Companion to the Young Brown Dwarf 2MASS J1207334-393254
• Multiplicity at the Stellar/Substellar Boundary in Upper Scorpius
• Multiplicity of very low-mass objects in the Upper Scorpius OB association: a possible wide binary population
• An Adaptive Optics Survey of M6.0-M7.5 Stars: Discovery of Three Very Low Mass Binary Systems Including Two Probable Hyades Members
• Oph 1622-2405: Not a Planetary-Mass Binary
• The first wide ultracool binary dwarf in the field: DENIS-J055146.0-443412.2 (M8.5 + L0)
• A New Brown Dwarf Desert? A Scarcity of Wide Ultracool Binaries
• Discovery of the Widest Very Low Mass Binary
• A Hubble Space Telescope ACS Search for Brown Dwarf Binaries in the Pleiades Open Cluster
• Spectroscopy of Young Planetary Mass Candidates with Disks
• Testing Theoretical Evolutionary Models with AB Dor C and the Initial Mass Function
• Discovery of a Wide Low-mass Binary System in Upper Scorpius
• A mid-infrared study of very low mass stars and brown dwarfs in Upper Scorpius
• Infrared Spectroscopy of the Ultra Low Mass Binary Oph 162225-240515

Cited by in corpus (79)

• Stellar Multiplicity
• A Revised Age for Upper Scorpius and The Star-Formation History Among the F-Type Members of the Scorpius-Centaurus OB Association
• Stellar, brown dwarf and multiple star properties from a radiation hydrodynamical simulation of star cluster formation
• Stellar, Brown Dwarf, and Multiple Star Properties from Hydrodynamical Simulations of Star Cluster Formation
• The Gemini Deep Planet Survey -- GDPS
• Adaptive Optics for Astronomy
• The Disk Population of the Upper Scorpius Association
• Characterizing Young Brown Dwarfs using Low Resolution Near-IR Spectra
• The Great Escape: How Exoplanets and Smaller Bodies Desert Dying Stars
• The Nature of Transition Circumstellar Disks I. The Ophiuchus Molecular Cloud
• On the evolution of a star cluster and its multiple stellar systems following gas dispersal
• Discovery of H-alpha Emission from the Close Companion Inside the Gap of Transitional Disk HD142527
• Sloan Low-Mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES): A Catalog of Very Wide, Low-mass Pairs
• Protoplanetary Disk Masses from Stars to Brown Dwarfs
• A Uniform Analysis of 118 Stars with High-Contrast Imaging: Long Period Extrasolar Giant Planets are Rare around Sun-like Stars
• The statistical properties of stars and their dependence on metallicity
• Unusually Wide Binaries: Are They Wide or Unusual?
• The statistical properties of stars and their dependence on metallicity: the effects of opacity
• Refining the Census of the Upper Scorpius Association with Gaia
• Discovery of a wide companion near the deuterium burning mass limit in the Upper Scorpius association
• The dependence of star formation on initial conditions and molecular cloud structure
• Constraints on Extrasolar Planet Populations from VLT NACO/SDI and MMT SDI and Direct Adaptive Optics Imaging Surveys: Giant Planets are Rare at Large Separations
• Star Formation via the Little Guy: A Bayesian Study of Ultracool Dwarf Imaging Surveys for Companions
• Measuring tiny mass accretion rates onto young brown dwarfs
• The GALEX Nearby Young-Star Survey
• Discovery of a Wide Binary Brown Dwarf Born in Isolation
• Constraining the multiplicity statistics of the coolest brown dwarfs: binary fraction continues to decrease with spectral type
• A Census of the Stellar Populations in the Sco-Cen Complex
• New Young Stars and Brown Dwarfs in the Upper Scorpius Association
• Towards Precise Ages and Masses of Free Floating Planetary Mass Brown Dwarfs
• OGLE-2013-BLG-0102LA,B: Microlensing binary with components at star/brown-dwarf and brown-dwarf/planet boundaries
• The low-mass population of the Rho Ophiuchi molecular cloud
• The LuckyCam Survey for Very Low Mass Binaries II: 13 new M4.5-M6.0 Binaries
• Reaching the boundary between stellar kinematic groups and very wide binaries. III. Sixteen new stars and eight new wide systems in the beta Pictoris moving group
• ULAS J141623.94+134836.3: a Blue T Dwarf Companion to a Blue L Dwarf
• Host star metallicity of directly imaged wide-orbit planets: implications for planet formation
• Identification of a Wide, Low-Mass Multiple System Containing the Brown Dwarf 2MASS J0850359+105716
• 2MASS 22344161+4041387AB: A Wide, Young, Accreting, Low-mass Binary in the LkHa233 Group
• Discovery of the Widest Very Low Mass Field Binary
• The Minimum Jeans Mass, Brown Dwarf Companion IMF, and Predictions for Detection of Y-type Dwarfs
• A Keck LGS AO Search for Brown Dwarf and Planetary Mass Companions to Upper Scorpius Brown Dwarfs
• A Search for Companions to Brown Dwarfs in the Taurus and Chamaeleon Star Forming Regions
• Accretion signatures in the X-shooter spectrum of the substellar companion to SR12
• A Search for Wide Companions to the Extrasolar Planetary System HR 8799
• Brown Dwarf Binaries from Disintegrating Triple Systems
• Gaia Assorted Mass Binaries Long Excluded from SLoWPoKES (GAMBLES): Identifying Ultra-Wide Binary Pairs with Components of Diverse Mass
• WISE2150-7520AB: A very low mass, wide co-moving brown dwarf system discovered through the citizen science project Backyard Worlds: Planet 9
• Shaping the Brown Dwarf Desert: Predicting the Primordial Brown Dwarf Binary Distributions from Turbulent Fragmentation
• A Substellar Common Proper Motion Companion to the Pleiad HII 1348
• Spectroscopy and kinematics of low-mass members of young moving groups
• Searching for Binary Y dwarfs with the Gemini Multi-Conjugate Adaptive Optics System (GeMS)
• USco1606-1935: An Unusually Wide Low-Mass Triple System?
• An optical spectroscopic H-R diagram for low-mass stars and brown dwarfs in Orion
• A wide planetary-mass companion to a young low-mass brown dwarf in Ophiuchus
• Resolved Spectroscopy of M Dwarf/L Dwarf Binaries. III. The "Wide" L3.5/L4 Dwarf Binary 2MASS J15500845+1455180AB
• Binary Formation in the Orion Nebula Cluster: Exploring the Sub-stellar Limit
• USco1621 B and USco1556 B: Two wide companions at the deuterium-burning mass limit in Upper Scorpius
• Discovery of wide low and very low-mass binary systems using Virtual Observatory tools
• KMT-2016-BLG-1820 and KMT-2016-BLG-2142: Two Microlensing Binaries Composed of Planetary-mass Companions and Very-Low-Mass Primaries
• On the Age of the Widest Very Low Mass Binary
• Formation of multiple low mass stars, brown dwarfs and planemos via gravitational collapse
• A low-mass triple system with a wide L/T transition brown dwarf component: NLTT 51469AB/SDSS 2131-0119
• Direct Imaging discovery of a second planet candidate around the possibly transiting planet host CVSO 30
• The search for planetary mass companions to field brown dwarfs with HST/NICMOS
• On the Binary Frequency of the Lowest Mass Members of the Pleiades with Hubble Space Telescope Wide Field Camera 3
• Strong H$\alpha$ emission in the young planetary mass companion 2MASS J0249-0557 c
• CWISE J014611.20-050850.0AB: The Widest Known Brown Dwarf Binary in the Field
• Reaching the boundary between stellar kinematic groups and very wide binaries. IV. The widest Washington double star systems with rho > 1000 arcsec in Gaia DR3
• 2MASS J11151597+1937266: A Young, Dusty, Isolated, Planetary-Mass Object with a Potential Wide Stellar Companion
• NICMOS Kernel-Phase Interferometry II: Demographics of Nearby Brown Dwarfs
• Precision measurement of a brown dwarf mass in a binary system in the microlensing event OGLE-2019-BLG-0033/MOA-2019-BLG-035
• Large Amplitude Photometric Variability of the Candidate Protoplanet TMR-1C
• A review on substellar objects beyond the deuterium burning mass limit: planets, brown dwarfs or what?
• Binary frequency of planet-host stars at wide separations: A new brown dwarf companion to a planet-host star
• The Brown Dwarf Kinematics Project (BDKP). II. Details on Nine Wide Common Proper Motion Very Low-Mass Companions to Nearby Stars
• Detection and characterisation of two VLM binaries: LP 1033-31 and LP 877-72
• The Perkins INfrared Exosatellite Survey (PINES) I. Survey Overview, Reduction Pipeline, and Early Results
• Ross 19B: An Extremely Cold Companion Discovered via the Backyard Worlds: Planet 9 Citizen Science Project
• Keck Observations in the INfrared of Taurus and $\rho$ Oph Exoplanets And Ultracool dwarfs (KOINTREAU) II: Two Young Bound Companions to Ophiuchus Stars