TY - JOUR
T1 - Direct-imaging Discovery and Dynamical Mass of a Substellar Companion Orbiting an Accelerating Hyades Sun-like Star with SCExAO/CHARIS
AU - Kuzuhara, Masayuki
AU - Currie, Thayne
AU - Takarada, Takuya
AU - Brandt, Timothy D.
AU - Sato, Bun’ei
AU - Uyama, Taichi
AU - Janson, Markus
AU - Chilcote, Jeffrey
AU - Tobin, Taylor
AU - Lawson, Kellen
AU - Hori, Yasunori
AU - Guyon, Olivier
AU - Groff, Tyler D.
AU - Lozi, Julien
AU - Vievard, Sebastien
AU - Sahoo, Ananya
AU - Deo, Vincent
AU - Jovanovic, Nemanja
AU - Ahn, Kyohoon
AU - Martinache, Frantz
AU - Skaf, Nour
AU - Akiyama, Eiji
AU - Norris, Barnaby R.
AU - Bonnefoy, Mickaël
AU - Hełminiak, Krzysztof G.
AU - Kudo, Tomoyuki
AU - McElwain, Michael W.
AU - Samland, Matthias
AU - Wagner, Kevin
AU - Wisniewski, John
AU - Knapp, Gillian R.
AU - Kwon, Jungmi
AU - Nishikawa, Jun
AU - Serabyn, Eugene
AU - Hayashi, Masahiko
AU - Tamura, Motohide
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/8/1
Y1 - 2022/8/1
N2 - We present the direct-imaging discovery of a substellar companion in orbit around a Sun-like star member of the Hyades open cluster. So far, no other substellar companions have been unambiguously confirmed via direct imaging around main-sequence stars in Hyades. The star HIP 21152 is an accelerating star as identified by the astrometry from the Gaia and Hipparcos satellites. We detected the companion, HIP 21152 B, in multiple epochs using the high-contrast imaging from SCExAO/CHARIS and Keck/NIRC2. We also obtained the stellar radial-velocity data from the Okayama 188 cm telescope. The CHARIS spectroscopy reveals that HIP 21152 B’s spectrum is consistent with the L/T transition, best fit by an early T dwarf. Our orbit modeling determines the semimajor axis and the dynamical mass of HIP 21152 B to be 17.5 − 3.8 + 7.2 au and 27.8 − 5.4 + 8.4 M Jup, respectively. The mass ratio of HIP 21152 B relative to its host is ≈2%, near the planet/brown dwarf boundary suggested by recent surveys. Mass estimates inferred from luminosity-evolution models are slightly higher (33-42 M Jup). With a dynamical mass and a well-constrained age due to the system’s Hyades membership, HIP 21152 B will become a critical benchmark in understanding the formation, evolution, and atmosphere of a substellar object as a function of mass and age. Our discovery is yet another key proof of concept for using precision astrometry to select direct-imaging targets.
AB - We present the direct-imaging discovery of a substellar companion in orbit around a Sun-like star member of the Hyades open cluster. So far, no other substellar companions have been unambiguously confirmed via direct imaging around main-sequence stars in Hyades. The star HIP 21152 is an accelerating star as identified by the astrometry from the Gaia and Hipparcos satellites. We detected the companion, HIP 21152 B, in multiple epochs using the high-contrast imaging from SCExAO/CHARIS and Keck/NIRC2. We also obtained the stellar radial-velocity data from the Okayama 188 cm telescope. The CHARIS spectroscopy reveals that HIP 21152 B’s spectrum is consistent with the L/T transition, best fit by an early T dwarf. Our orbit modeling determines the semimajor axis and the dynamical mass of HIP 21152 B to be 17.5 − 3.8 + 7.2 au and 27.8 − 5.4 + 8.4 M Jup, respectively. The mass ratio of HIP 21152 B relative to its host is ≈2%, near the planet/brown dwarf boundary suggested by recent surveys. Mass estimates inferred from luminosity-evolution models are slightly higher (33-42 M Jup). With a dynamical mass and a well-constrained age due to the system’s Hyades membership, HIP 21152 B will become a critical benchmark in understanding the formation, evolution, and atmosphere of a substellar object as a function of mass and age. Our discovery is yet another key proof of concept for using precision astrometry to select direct-imaging targets.
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U2 - 10.3847/2041-8213/ac772f
DO - 10.3847/2041-8213/ac772f
M3 - Article
AN - SCOPUS:85149579861
SN - 2041-8205
VL - 934
JO - Astrophysical Journal Letters
JF - Astrophysical Journal Letters
IS - 2
M1 - L19
ER -