Direct Spectrum of the Benchmark T dwarf HD 19467 B

Abstract

HD 19467 B is presently the only directly imaged T dwarf companion known to induce a measurable Doppler acceleration around a solar type star. We present spectroscopy measurements of this important benchmark object taken with the Project 1640 integral field unit at Palomar Observatory. Our high-contrast R~30 observations obtained simultaneously across the $JH$ bands confirm the cold nature of the companion as reported from the discovery article and determine its spectral type for the first time. Fitting the measured spectral energy distribution to SpeX/IRTF T dwarf standards and synthetic spectra from BT-Settl atmospheric models, we find that HD 19467 B is a T5.5+/-1 dwarf with effective temperature Teff=$978_{-43}^{+20}$ K. Our observations reveal significant methane absorption affirming its substellar nature. HD 19467 B shows promise to become the first T dwarf that simultaneously reveals its mass, age, and metallicity independent from the spectrum of light that it emits.

Accepted to ApJ Letters

References in corpus (12)

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Cited by in corpus (11)

• Population-Level Eccentricity Distributions of Imaged Exoplanets and Brown Dwarf Companions: Dynamical Evidence for Distinct Formation Channels
• Improved Dynamical Masses for Six Brown Dwarf Companions Using Hipparcos and Gaia EDR3
• A survey of the linear polarization of directly imaged exoplanets and brown dwarf companions with SPHERE-IRDIS. First polarimetric detections revealing disks around DH Tau B and GSC 6214-210 B
• The Orbital Eccentricities of Directly Imaged Companions Using Observable-Based Priors: Implications for Population-level Distributions
• Orbital and spectral characterization of the benchmark T-type brown dwarf HD 19467B
• First Observations of the Brown Dwarf HD 19467 B with JWST
• Spectroscopic binaries in the Solar Twin Planet Search program: from substellar-mass to M dwarf companions
• Surveying Nearby Brown Dwarfs with HGCA: Direct Imaging Discovery of a Faint, High-Mass Brown Dwarf Orbiting HD 176535 A
• Characterising brown dwarf companions with IRDIS long-slit spectroscopy: HD 1160 B and HD 19467 B
• Discovery of a resolved white dwarf-brown dwarf binary with a small projected separation: SDSS J222551.65+001637.7AB
• JWST high-contrast spectroscopy with speckle modelling: Atmospheric retrievals of the T dwarf companion HD 19467 B