TY - JOUR
T1 - SCExAO/CHARIS Direct Imaging Discovery of a 20 au Separation, Low-mass Ratio Brown Dwarf Companion to an Accelerating Sun-like Star
AU - Currie, Thayne
AU - Brandt, Timothy D.
AU - Kuzuhara, Masayuki
AU - Chilcote, Jeffrey
AU - Guyon, Olivier
AU - Marois, Christian
AU - Groff, Tyler D.
AU - Lozi, Julien
AU - Vievard, Sebastien
AU - Sahoo, Ananya
AU - Deo, Vincent
AU - Jovanovic, Nemanja
AU - Martinache, Frantz
AU - Wagner, Kevin
AU - Dupuy, Trent
AU - Wahl, Matthew
AU - Letawsky, Michael
AU - Li, Yiting
AU - Zeng, Yunlin
AU - Brandt, G. Mirek
AU - Michalik, Daniel
AU - Grady, Carol
AU - Janson, Markus
AU - Knapp, Gillian R.
AU - Kwon, Jungmi
AU - Lawson, Kellen
AU - McElwain, Michael W.
AU - Uyama, Taichi
AU - Wisniewski, John
AU - Tamura, Motohide
N1 - Publisher Copyright:
© 2020. The American Astronomical Society. All rights reserved..
PY - 2020/12/1
Y1 - 2020/12/1
N2 - We present the direct imaging discovery of a substellar companion to the nearby Sun-like star, HD 33632 Aa, at a projected separation of ∼20 au, obtained with SCExAO/CHARIS integral field spectroscopy complemented by Keck/NIRC2 thermal infrared imaging. The companion, HD 33632 Ab, induces a 10.5σ astrometric acceleration on the star as detected with the Gaia and Hipparcos satellites. SCExAO/CHARIS JHK (1.1-2.4 μm) spectra and Keck/NIRC2 L p (3.78 μm) photometry are best matched by a field L/T transition object: An older, higher-gravity, and less dusty counterpart to HR 8799 cde. Combining our astrometry with Gaia/Hipparcos data and archival Lick Observatory radial velocities, we measure a dynamical mass of 46.4 ± 8 M J and an eccentricity of e < 0.46 at 95% confidence. HD 33632 Ab's mass and mass ratio (4.0% ± 0.7%) are comparable to the low-mass brown dwarf GJ 758 B and intermediate between the more massive brown dwarf HD 19467 B and the (near-)planet-mass companions to HR 2562 and GJ 504. Using Gaia to select for direct imaging observations with the newest extreme adaptive optics systems can reveal substellar or even planet-mass companions on solar system-like scales at an increased frequency compared to blind surveys.
AB - We present the direct imaging discovery of a substellar companion to the nearby Sun-like star, HD 33632 Aa, at a projected separation of ∼20 au, obtained with SCExAO/CHARIS integral field spectroscopy complemented by Keck/NIRC2 thermal infrared imaging. The companion, HD 33632 Ab, induces a 10.5σ astrometric acceleration on the star as detected with the Gaia and Hipparcos satellites. SCExAO/CHARIS JHK (1.1-2.4 μm) spectra and Keck/NIRC2 L p (3.78 μm) photometry are best matched by a field L/T transition object: An older, higher-gravity, and less dusty counterpart to HR 8799 cde. Combining our astrometry with Gaia/Hipparcos data and archival Lick Observatory radial velocities, we measure a dynamical mass of 46.4 ± 8 M J and an eccentricity of e < 0.46 at 95% confidence. HD 33632 Ab's mass and mass ratio (4.0% ± 0.7%) are comparable to the low-mass brown dwarf GJ 758 B and intermediate between the more massive brown dwarf HD 19467 B and the (near-)planet-mass companions to HR 2562 and GJ 504. Using Gaia to select for direct imaging observations with the newest extreme adaptive optics systems can reveal substellar or even planet-mass companions on solar system-like scales at an increased frequency compared to blind surveys.
KW - Astronomical instrumentation(799)
KW - Astronomical optics (88)
KW - Astronomical techniques (1684)
KW - Brown dwarfs (185)
KW - Coronagraphic imaging (313)
KW - Direct imaging (387)
KW - Exoplanet detection methods(489)
KW - Exoplanets (498)
UR - https://www.scopus.com/pages/publications/85097510090
UR - https://www.scopus.com/pages/publications/85097510090#tab=citedBy
U2 - 10.3847/2041-8213/abc631
DO - 10.3847/2041-8213/abc631
M3 - Article
AN - SCOPUS:85097510090
SN - 2041-8205
VL - 904
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L25
ER -