TY - JOUR
T1 - SCExAO/CHARIS Direct Imaging of A Low-mass Companion at A Saturn-like Separation from an Accelerating Young A7 Star
AU - Chilcote, Jeffrey
AU - Tobin, Taylor
AU - Currie, Thayne
AU - Brandt, Timothy D.
AU - Groff, Tyler D.
AU - Kuzuhara, Masayuki
AU - Guyon, Olivier
AU - Lozi, Julien
AU - Jovanovic, Nemanja
AU - Sahoo, Ananya
AU - Deo, Vincent
AU - Akiyama, Eiji
AU - Janson, Markus
AU - Knapp, Jill
AU - Kwon, Jungmi
AU - McElwain, Michael W.
AU - Nishikawa, Jun
AU - Wagner, Kevin
AU - Hełminiak, Krzysztof
AU - Skaf, Nour
AU - Tamura, Motohide
N1 - Publisher Copyright:
© 2021. The American Astronomical Society. All rights reserved..
PY - 2021/12/1
Y1 - 2021/12/1
N2 - We present the SCExAO direct imaging discovery and characterization of a low-mass companion to the nearby young A7IV star, HD 91312. SCExAO/CHARIS JHK (1.1-2.4 μm) spectra and SCExAO/HiCIAO H-band imaging identify the companion over a two year baseline in a highly inclined orbit with a maximum projected separation of 8 au. The companion, HD 91312 B, induces an 8.8σ astrometric acceleration on the star as seen with the Gaia & Hipparcos satellites and a long-term radial-velocity trend as previously identified by Borgniet et al. HD 91312 B's spectrum is consistent with that of an early-to-mid M dwarf. Hipparcos and Gaia absolute astrometry, radial-velocity data, and SCExAO/CHARIS astrometry constrain its dynamical mass to be 0.337-0.044+0.042 M o˙, consistent with - but far more precise than - masses derived from spectroscopy, and favors a nearly edge-on orbit with a semimajor axis of ∼9.7 au. This work is an example of precisely characterizing properties of low-mass companions at solar system-like scales from a combination of direct imaging, astrometry, and radial-velocity methods.
AB - We present the SCExAO direct imaging discovery and characterization of a low-mass companion to the nearby young A7IV star, HD 91312. SCExAO/CHARIS JHK (1.1-2.4 μm) spectra and SCExAO/HiCIAO H-band imaging identify the companion over a two year baseline in a highly inclined orbit with a maximum projected separation of 8 au. The companion, HD 91312 B, induces an 8.8σ astrometric acceleration on the star as seen with the Gaia & Hipparcos satellites and a long-term radial-velocity trend as previously identified by Borgniet et al. HD 91312 B's spectrum is consistent with that of an early-to-mid M dwarf. Hipparcos and Gaia absolute astrometry, radial-velocity data, and SCExAO/CHARIS astrometry constrain its dynamical mass to be 0.337-0.044+0.042 M o˙, consistent with - but far more precise than - masses derived from spectroscopy, and favors a nearly edge-on orbit with a semimajor axis of ∼9.7 au. This work is an example of precisely characterizing properties of low-mass companions at solar system-like scales from a combination of direct imaging, astrometry, and radial-velocity methods.
UR - https://www.scopus.com/pages/publications/85120827517
UR - https://www.scopus.com/pages/publications/85120827517#tab=citedBy
U2 - 10.3847/1538-3881/ac29ba
DO - 10.3847/1538-3881/ac29ba
M3 - Article
AN - SCOPUS:85120827517
SN - 0004-6256
VL - 162
JO - Astronomical Journal
JF - Astronomical Journal
IS - 6
M1 - 251
ER -