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Large Adaptive Optics Survey for Substellar Objects around Young, Nearby, Low-mass Stars with Robo-AO

Salama, Maïssa and Ou, James and Baranec, Christoph and Liu, Michael C. and Bowler, Brendan P. and Barnes, Paul and Bonnet, Morgan and Chun, Mark and Duev, Dmitry A. and Goebel, Sean and Hall, Don and Jacobson, Shane and Jensen-Clem, Rebecca and Law, Nicholas M. and Lockhart, Charles and Riddle, Reed and Situ, Heather and Warmbier, Eric and Zhang, Zhoujian (2021) Large Adaptive Optics Survey for Substellar Objects around Young, Nearby, Low-mass Stars with Robo-AO. Astronomical Journal, 162 (3). Art. No. 102. ISSN 0004-6256. doi:10.3847/1538-3881/ac0445.

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We present results from the Large Adaptive optics Survey for Substellar Objects, where the goal is to directly image new substellar companions (<70 M_(Jup)) at wide orbital separations (≳50 au) around young (≲300 Myr), nearby (<100 pc), low-mass (≈0.1–0.8 M_⊙) stars. We report on 427 young stars imaged in the visible (i') and near-infrared (J or H ) simultaneously with Robo-AO on the Kitt Peak 2.1 m telescope and later the Maunakea University of Hawaii 2.2 m telescope. To undertake the observations, we commissioned a new infrared camera for Robo-AO that uses a low-noise high-speed SAPHIRA avalanche photodiode detector. We detected 121 companion candidates around 111 stars, of which 62 companions are physically associated based on Gaia DR2 parallaxes and proper motions, another 45 require follow-up observations to confirm physical association, and 14 are background objects. The companion separations range from 2 to 1101 au and reach contrast ratios of 7.7 mag in the near-infrared compared to the primary. The majority of confirmed and pending candidates are stellar companions, with ∼5 being potentially substellar and requiring follow-up observations for confirmation. We also detected a 43 ± 9 M_(Jup) and an 81 ± 5 M_(Jup) companion that were previously reported. We found 34 of our targets have acceleration measurements detected using Hipparcos–Gaia proper motions. Of those, 58₋₁₄⁺¹²% of the 12 stars with imaged companion candidates have significant accelerations (χ² > 11.8), while only 23₋₆⁺¹¹% of the remaining 22 stars with no detected companion have significant accelerations. The significance of the acceleration decreases with increasing companion separation. These young accelerating low-mass stars with companions will eventually yield dynamical masses with future orbit monitoring.

Item Type:Article
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URLURL TypeDescription Paper
Salama, Maïssa0000-0002-5082-6332
Ou, James0000-0002-8439-7767
Baranec, Christoph0000-0002-1917-9157
Liu, Michael C.0000-0003-2232-7664
Bowler, Brendan P.0000-0003-2649-2288
Chun, Mark0000-0002-8462-0703
Duev, Dmitry A.0000-0001-5060-8733
Goebel, Sean0000-0003-3763-2418
Jensen-Clem, Rebecca0000-0003-0054-2953
Law, Nicholas M.0000-0001-9380-6457
Riddle, Reed0000-0002-0387-370X
Zhang, Zhoujian0000-0002-3726-4881
Alternate Title:Large Adaptive Optics Survey for Substellar Objects (LASSO) Around Young, Nearby, Low-mass Stars with Robo-AO
Additional Information:© 2021. The American Astronomical Society. Received 2020 November 11; revised 2021 May 17; accepted 2021 May 19; published 2021 August 13. The authors are honored to be permitted to conduct astronomical research on Iolkam Du'ag (Kitt Peak), a mountain with particular significance to the Tohono O'odham Nation. The authors also wish to recognize and acknowledge the very significant cultural role and reverence that the summit of Maunakea has always had within the indigenous Hawaiian community. We are most fortunate to have the opportunity to conduct observations from both mountains. We are grateful to the Kitt Peak National Observatory and UH88'' staff for their support of Robo-AO on the 2.1 m and 2.2 m telescopes, respectively. We thank Shri Kulkarni for his sustained backing of Robo-AO through all its iterations, Dani Atkinson for help understanding the intricacies of the SAPHIRA detectors, and Bo Reipurth for valuable discussions and comments on the manuscript. We are grateful to Adwin Boogert for observing 2MASS J16304072-2018186 and its companion with IRTF/SpeX. The Robo-AO system is supported by collaborating partner institutions, the California Institute of Technology and the Inter-University Centre for Astronomy and Astrophysics, and by the National Science Foundation under grant Nos. AST-0906060, AST-0960343, and AST-1207891, by the Mount Cuba Astronomical Foundation, and by a gift from Samuel Oschin. As part of the development of Robo-AO-2, Robo-AO at the UH 2.2 m telescope system is supported by the National Science Foundation under grant No. AST-1712014, the State of Hawaii Capital Improvement Projects, and by a gift from the Lumb Family. M.C.L. acknowledges support from National Science Foundation grant AST-1518339. B.P.B. acknowledges support from the National Science Foundation grant AST-1909209. This work has made use of data from the European Space Agency (ESA) mission Gaia (, processed by the Gaia Data Processing and Analysis Consortium (DPAC, Funding for the DPAC has been provided by national institutions, in particular the institutions participating in the Gaia Multilateral Agreement. This research has made use of the VizieR catalog access tool, CDS, Strasbourg, France (DOI:10.26093/cds/vizier). The original description of the VizieR service was published in A&AS 143, 23. This research has made use of the SIMBAD database, operated by Centre des Données Stellaires (Strasbourg, France), and bibliographic references from the Astrophysics Data System maintained by SAO/NASA. This publication has made use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This research has made use of the SVO Filter Profile Service ( supported from the Spanish MINECO through grant AYA2017-84089. This research has made use of the Washington Double Star Catalog maintained at the US Naval Observatory. Facility: KPNO:2.1 m (Robo-AO), UH:2.2 m (Robo-AO), IRTF (SpeX). Software: ExoDMC (v1.1b; Bonavita 2020), Spextool (v4.1; Cushing et al. 2004).
Funding AgencyGrant Number
Inter-University Centre for Astronomy and AstrophysicsUNSPECIFIED
Mt. Cuba Astronomical FoundationUNSPECIFIED
State of Hawaii Capital Improvement ProjectsUNSPECIFIED
Gaia Multilateral AgreementUNSPECIFIED
Ministerio de Economía, Industria y Competitividad (MINECO)AYA2017-84089
Subject Keywords:Low mass stars; Binary stars; Brown dwarfs; Surveys; Optical observation; Infrared astronomy; Astronomical instrumentation
Issue or Number:3
Classification Code:Unified Astronomy Thesaurus concepts: Low mass stars (2050); Binary stars (154); Brown dwarfs (185); Surveys (1671); Optical observation (1169); Infrared astronomy (786); Astronomical instrumentation (799)
Record Number:CaltechAUTHORS:20210603-122527071
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Official Citation:Maïssa Salama et al 2021 AJ 162 102
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:109368
Deposited By: George Porter
Deposited On:03 Jun 2021 22:13
Last Modified:15 Sep 2021 18:14

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