CaltechAUTHORS
  A Caltech Library Service

SCExAO/CHARIS Direct Imaging Discovery of a 20 au Separation, Low-mass Ratio Brown Dwarf Companion to an Accelerating Sun-like Star

Currie, Thayne and Brandt, Timothy D. and Kuzuhara, Masayuki and Chilcote, Jeffrey and Guyon, Olivier and Marois, Christian and Groff, Tyler D. and Lozi, Julien and Vievard, Sebastien and Sahoo, Ananya and Deo, Vincent and Jovanovic, Nemanja and Martinache, Frantz and Wagner, Kevin and Dupuy, Trent and Wahl, Matthew and Letawsky, Michael and Li, Yiting and Zeng, Yunlin and Brandt, G. Mirek and Michalik, Daniel and Grady, Carol and Janson, Markus and Knapp, Gillian R. and Kwon, Jungmi and Lawson, Kellen and McElwain, Michael W. and Uyama, Taichi and Wisniewski, John and Tamura, Motohide (2020) SCExAO/CHARIS Direct Imaging Discovery of a 20 au Separation, Low-mass Ratio Brown Dwarf Companion to an Accelerating Sun-like Star. Astrophysical Journal Letters, 904 (2). Art. No. L25. ISSN 2041-8213. https://resolver.caltech.edu/CaltechAUTHORS:20201204-110356649

[img] PDF - Published Version
See Usage Policy.

1929Kb
[img] PDF - Accepted Version
See Usage Policy.

2021Kb

Use this Persistent URL to link to this item: https://resolver.caltech.edu/CaltechAUTHORS:20201204-110356649

Abstract

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.


Item Type:Article
Related URLs:
URLURL TypeDescription
https://doi.org/10.3847/2041-8213/abc631DOIArticle
https://arxiv.org/abs/2011.08855arXivDiscussion Paper
ORCID:
AuthorORCID
Currie, Thayne0000-0002-7405-3119
Brandt, Timothy D.0000-0003-2630-8073
Kuzuhara, Masayuki0000-0002-4677-9182
Chilcote, Jeffrey0000-0001-6305-7272
Guyon, Olivier0000-0002-1097-9908
Marois, Christian0000-0002-4164-4182
Groff, Tyler D.0000-0001-5978-3247
Lozi, Julien0000-0002-3047-1845
Vievard, Sebastien0000-0003-4018-2569
Sahoo, Ananya0000-0003-2806-1254
Jovanovic, Nemanja0000-0001-5213-6207
Martinache, Frantz0000-0003-1180-4138
Wagner, Kevin0000-0002-4309-6343
Dupuy, Trent0000-0001-9823-1445
Brandt, G. Mirek0000-0003-0168-3010
Michalik, Daniel0000-0002-7618-6556
Grady, Carol0000-0001-5440-1879
Janson, Markus0000-0001-8345-593X
Knapp, Gillian R.0000-0002-9259-1164
Kwon, Jungmi0000-0003-2815-7774
Lawson, Kellen0000-0002-6964-8732
McElwain, Michael W.0000-0003-0241-8956
Uyama, Taichi0000-0002-6879-3030
Wisniewski, John0000-0001-9209-1808
Tamura, Motohide0000-0002-6510-0681
Additional Information:© 2020. The American Astronomical Society. Received 2020 September 19; revised 2020 October 21; accepted 2020 October 30; published 2020 November 30. Based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. We thank Eric Mamajek and William Cochran for helpful comments regarding the HD 33632 system properties. The authors acknowledge the very significant cultural role and reverence that the summit of Maunakea holds within the Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. We acknowledge the critical importance of the current and recent Subaru and Keck Observatory daycrew, technicians, support astronomers, telescope operators, computer support, and office staff employees, especially during the challenging times presented by the COVID-19 pandemic. Their expertise, ingenuity, and dedication is indispensable to the continued successful operation of these observatories. We thank the Subaru and NASA Keck Time Allocation Committees for their generous support of this program. T.C. was supported by a NASA Senior Postdoctoral Fellowship and NASA/Keck grant LK-2663-948181. T.B. gratefully acknowledges support from the Heising-Simons foundation and from NASA under grant #80NSSC18K0439. M.T. is supported by JSPS KAKENHI grant #18H05442. The development of SCExAO was supported by JSPS (Grant-in-Aid for Research #23340051, #26220704, and #23103002), Astrobiology Center of NINS, Japan, the Mt Cuba Foundation, and the director's contingency fund at Subaru Telescope. CHARIS was developed under the support by the Grant-in-Aid for Scientific Research on Innovative Areas #2302. 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.
Group:Infrared Processing and Analysis Center (IPAC)
Funders:
Funding AgencyGrant Number
NASA Postdoctoral ProgramUNSPECIFIED
NASALK-2663-948181
NASA80NSSC18K0439
Japan Society for the Promotion of Science (JSPS)18H05442
NASA Hubble FellowshipUNSPECIFIED
NASA Sagan FellowshipUNSPECIFIED
Japan Society for the Promotion of Science (JSPS)23340051
Japan Society for the Promotion of Science (JSPS)26220704
Japan Society for the Promotion of Science (JSPS)23103002
National Institutes of Natural Sciences of JapanUNSPECIFIED
Mt. Cuba Astronomical FoundationUNSPECIFIED
Subaru TelescopeUNSPECIFIED
Japan Society for the Promotion of Science (JSPS)2302
W. M. Keck FoundationUNSPECIFIED
Heising-Simons FoundationUNSPECIFIED
Subject Keywords:Exoplanets ; Brown dwarfs ; Astronomical instrumentation ; Astronomical optics ; Direct imaging ; Coronagraphic imaging ; Exoplanet detection methods ; Astronomical techniques
Issue or Number:2
Classification Code:Unified Astronomy Thesaurus concepts: Exoplanets (498); Brown dwarfs (185); Astronomical instrumentation (799); Astronomical optics (88); Direct imaging (387); Coronagraphic imaging (313); Exoplanet detection methods (489); Astronomical techniques (1684)
Record Number:CaltechAUTHORS:20201204-110356649
Persistent URL:https://resolver.caltech.edu/CaltechAUTHORS:20201204-110356649
Official Citation:Thayne Currie et al 2020 ApJL 904 L25
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:106912
Collection:CaltechAUTHORS
Deposited By: George Porter
Deposited On:05 Dec 2020 01:32
Last Modified:05 Dec 2020 01:32

Repository Staff Only: item control page