Resolved Spectroscopy of M Dwarf/L Dwarf Binaries. IV. Discovery of an M9 + L6 BInary Separated by Over 100 AU

Abstract

We report the discovery of a faint L6 \pm 1 companion to the previously known M9 dwarf, 2MASS J01303563-4445411, based on our near-infrared imaging and spectroscopic observations with the 3m Infrared Telescope Facility SpeX imager/spectrometer. The visual binary is separated by 3. 28 \pm 0. 05 on the sky at a spectrophotometric distance of 40 \pm 14 pc. The projected physical separation is 130 \pm 50 AU, making it one of the widest VLM field multiples containing a brown dwarf companion. 2MASS J0130-4445 is only one of ten wide VLM pairs and only one of six in the field. The secondary is considerably fainter (ΔK ~ 2.35 mag) and redder (Δ (J - Ks) ~ 0.81 dex), consistent with component near-infrared types of M9.0 \pm 0.5 and L6 \pm 1 based on our resolved spectroscopy. The component types suggest a secondary mass well within the hydrogen-burning limit and an age-dependent mass ratio of 0.6-0.9. The system's space motion and spectroscopic indicators suggest an age of 2-4 Gyr while the model-dependent masses and binding energies suggest that this system is unlikely to have formed via dynamical ejection. The age, composition, and separation of the 2MASS J01303563-4445411 system make it useful for tests of VLM formation theories and of condensate cloud formation in L dwarfs.

Accepted by the AJ (8 pages, emulateapj format)

References in corpus (25)

• 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
• The Luminosity and Mass Functions of Low-Mass Stars in the Galactic Disk: II. The Field
• The First Direct Measurements of Magnetic Fields on Very Low-Mass Stars
• Effect of episodic accretion on the structure and the lithium depletion of low-mass stars and planet-hosting stars
• Radio Observations of a Large Sample of Late-M, L, and T Dwarfs: The Distribution of Magentic Field Strengths
• A Sample of Very Young Field L Dwarfs and Implications for the Brown Dwarf "Lithium Test" at Early Ages
• Activity and Kinematics of Ultracool Dwarfs Including An Amazing Flare Observation
• Subtle Signatures of Multiplicity in Late-type Dwarf Spectra: The Unresolved M8.5 + T5 Binary 2MASS J03202839-0446358
• Discovery of Two Nearby, Peculiar L Dwarfs from the 2MASS Proper Motion Survey: Young or Metal-Rich?
• New Distant Companions to Known Nearby Stars. II. Faint companions of Hipparcos stars and the frequency of wide binary systems
• Sloan Low-Mass Wide Pairs of Kinematically Equivalent Stars (SLoWPoKES): A Catalog of Very Wide, Low-mass Pairs
• A Survey for Spectroscopic Binaries Among Very Low-Mass Stars
• Optical Spectroscopy of 2MASS Color-Selected Ultracool Subdwarfs
• Finding benchmark brown dwarfs to probe the IMF as a function of time
• Discovery of a T Dwarf Binary with the Largest Known J-Band Flux Reversal
• Discovery of new nearby L and late-M dwarfs at low Galactic latitude from the DENIS database
• Searching for Earth analogues around the nearest stars: the disk age-metallicity relation and the age distribution in the Solar Neighbourhood
• Binary frequency of very young brown dwarfs at separations smaller than 3 AU
• Discovery of a High Proper Motion L Dwarf Binary: 2MASS J15200224-4422419AB
• Near-infrared low-resolution spectroscopy of Pleiades L-type brown dwarfs
• Discovery of a nearby L-T transition object in the Southern Galactic plane
• Resolved Spectroscopy of M Dwarf/L Dwarf Binaries. II. 2MASS J 17072343-0558249AB
• Identification of the Lithium Depletion Boundary and Age of the Southern Open Cluster Blanco 1
• The Minimum Jeans Mass, Brown Dwarf Companion IMF, and Predictions for Detection of Y-type Dwarfs

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• 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
• WISE2150-7520AB: A very low mass, wide co-moving brown dwarf system discovered through the citizen science project Backyard Worlds: Planet 9
• SLoWPoKES-II: 100,000 Wide Binaries Identified in SDSS without Proper Motions
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• KMT-2016-BLG-1820 and KMT-2016-BLG-2142: Two Microlensing Binaries Composed of Planetary-mass Companions and Very-Low-Mass Primaries
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• COol Companions ON Ultrawide orbiTS (COCONUTS). III. A Very Red L6 Benchmark Brown Dwarf around a Young M5 Dwarf
• A Novel Survey for Young Substellar Objects with the W-band filter III: Searching for very low mass brown dwarfs in Serpens South and Serpens Core
• The formation of low-mass stars and brown dwarfs