TY - JOUR
T1 - SCExAO and Keck Direct Imaging Discovery of a Low-mass Companion Around the Accelerating F5 Star HIP 5319* * Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. Some of the data presented herein were obtained at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W. M. Keck Foundation. This work makes use of observations from the Las Cumbres Observatory global telescope network (LCOGT).
AU - Swimmer, Noah
AU - Currie, Thayne
AU - Steiger, Sarah
AU - Brandt, G. Mirek
AU - Brandt, Timothy D.
AU - Guyon, Olivier
AU - Kuzuhara, Masayuki
AU - Chilcote, Jeffrey
AU - Tobin, Taylor
AU - Groff, Tyler D.
AU - Lozi, Julien
AU - Bailey, John I.
AU - Walter, Alexander B.
AU - Fruitwala, Neelay
AU - Zobrist, Nicholas
AU - Smith, Jennifer Pearl
AU - Coiffard, Gregoire
AU - Dodkins, Rupert
AU - Davis, Kristina K.
AU - Daal, Miguel
AU - Bumble, Bruce
AU - Vievard, Sebastien
AU - Skaf, Nour
AU - Deo, Vincent
AU - Jovanovic, Nemanja
AU - Martinache, Frantz
AU - Tamura, Motohide
AU - Kasdin, N. Jeremy
AU - Mazin, Benjamin A.
N1 - Publisher Copyright:
© 2022. The Author(s). Published by the American Astronomical Society.
PY - 2022/10/1
Y1 - 2022/10/1
N2 - We present the direct imaging discovery of a low-mass companion to the nearby accelerating F star, HIP 5319, using SCExAO coupled with the CHARIS, VAMPIRES, and MEC instruments in addition to Keck/NIRC2 imaging. CHARIS JHK (1.1-2.4 μm) spectroscopic data combined with VAMPIRES 750 nm, MEC Y, and NIRC2 L p photometry is best matched by an M3-M7 object with an effective temperature of T = 3200 K and surface gravity log(g) = 5.5. Using the relative astrometry for HIP 5319 B from CHARIS and NIRC2, and absolute astrometry for the primary from Gaia and Hipparcos, and adopting a log-normal prior assumption for the companion mass, we measure a dynamical mass for HIP 5319 B of 31 − 11 + 35 M J , a semimajor axis of 18.6 − 4.1 + 10 au, an inclination of 69.4 − 15 + 5.6 degrees, and an eccentricity of 0.42 − 0.29 + 0.39 . However, using an alternate prior for our dynamical model yields a much higher mass of 128 − 88 + 127 M J . Using data taken with the LCOGT NRES instrument we also show that the primary HIP 5319 A is a single star in contrast to previous characterizations of the system as a spectroscopic binary. This work underscores the importance of assumed priors in dynamical models for companions detected with imaging and astrometry, and the need to have an updated inventory of system measurements.
AB - We present the direct imaging discovery of a low-mass companion to the nearby accelerating F star, HIP 5319, using SCExAO coupled with the CHARIS, VAMPIRES, and MEC instruments in addition to Keck/NIRC2 imaging. CHARIS JHK (1.1-2.4 μm) spectroscopic data combined with VAMPIRES 750 nm, MEC Y, and NIRC2 L p photometry is best matched by an M3-M7 object with an effective temperature of T = 3200 K and surface gravity log(g) = 5.5. Using the relative astrometry for HIP 5319 B from CHARIS and NIRC2, and absolute astrometry for the primary from Gaia and Hipparcos, and adopting a log-normal prior assumption for the companion mass, we measure a dynamical mass for HIP 5319 B of 31 − 11 + 35 M J , a semimajor axis of 18.6 − 4.1 + 10 au, an inclination of 69.4 − 15 + 5.6 degrees, and an eccentricity of 0.42 − 0.29 + 0.39 . However, using an alternate prior for our dynamical model yields a much higher mass of 128 − 88 + 127 M J . Using data taken with the LCOGT NRES instrument we also show that the primary HIP 5319 A is a single star in contrast to previous characterizations of the system as a spectroscopic binary. This work underscores the importance of assumed priors in dynamical models for companions detected with imaging and astrometry, and the need to have an updated inventory of system measurements.
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U2 - 10.3847/1538-3881/ac85a8
DO - 10.3847/1538-3881/ac85a8
M3 - Article
AN - SCOPUS:85139451397
SN - 0004-6256
VL - 164
JO - Astronomical Journal
JF - Astronomical Journal
IS - 4
M1 - 152
ER -