Haro 5-2: A New Pre-main-sequence Quadruple Stellar System
Creators
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1.
California Institute of Technology
Abstract
We have discovered that the Hα emission-line star Haro 5-2, located in the 3–6 Myr old Ori OB1b association, is a young quadruple system. The system has a 2+2 configuration, with an outer separation of 2.″6 and with resolved subarcsecond inner binary components. The brightest component, Aa, dominates the A-binary; it is a weak-line T Tauri star with spectral type M2.5±1. The two stars of the B component are equally bright at J, but the Bb star is much redder. Optical spectroscopy of the combined B pair indicates a rich emission-line spectrum with a M3±1 spectral type. The spectrum is highly variable and switches back and forth between a classical and a weak-line T Tauri star. In the near-IR, the spectrum shows Paschen β and Brackett γ in emission, indicative of active accretion. A significant mid-IR excess reveals the presence of circumstellar or circumbinary material in the system. Most multiple systems are likely formed during the protostellar phase, involving flybys of neighboring stars followed by an inspiraling phase driven by accretion from circumbinary material and leading to compact subsystems. However, Haro 5-2 stands out among young 2+2 quadruples, as the two inner binaries are unusually wide relative to the separation of the A and B pair, allowing future studies of the individual components. Assuming the components are coeval, the system could potentially allow stringent tests of pre-main-sequence evolutionary models.
Copyright and License
© 2024. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
Acknowledgement
We thank A. Tokovinin and J. A. Caballero for valuable comments, and A. Tokovinin for providing the data in Table 4.
Based in part on observations obtained at the International Gemini Observatory, a program of NSF's NOIRLAB, which is managed by the Association of Universities for Research in Astronomy (AURA), under a cooperative agreement with the National Science Foundation, on behalf of the Gemini partnership: the National Science Foundation (United States), the National Research Council (Canada), Agencia Nacional de Investigación y Desarollo (Chile), Ministerio de Ciencia, Tecnologia e Innovación (Argentina), Ministerio da Ciencia, Technologia, Inovacoes e Comunicacoes (Brazil), and the Korea Astronomy and Space Science Institute (Republic of Korea).
It is also based in part on observations obtained at the Southern Astrophysical Research (SOAR) telescope, which is a joint project of the Ministério da Ciência, Tecnologia e Inovações (MCTI/LNA) do Brasil, the US National Science Foundation's NOIRLab, the University of North Carolina at Chapel Hill (UNC), and Michigan State University (MSU). IRAF was distributed by the National Optical Astronomy Observatory, which was managed by the Association of Universities for Research in Astronomy (AURA), under a cooperative agreement with the National Science Foundation.
The Robo-AO system is supported by collaborating partner institutions, the California Institute of Technology, the Inter-University Centre for Astronomy and Astrophysics, the National Science Foundation under grant Nos. AST-0906060, AST-0960343, and AST1207891, a grant from the Mt. Cuba Astronomical Foundation, and a gift from Samuel Oschin.
This paper includes data collected by the TESS mission. Funding for the TESS mission is provided by NASA's Science Mission Directorate.
This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France, and of NASA's Astrophysics Data System Bibliographic Services.
This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al. 2013, 2018, 2022). We are grateful to Katelyn Allers for her detailed and instructive YouTube videos on reducing TSpec data: https://www.youtube.com/user/katelynallers/videos.
Facilities
PO: 1.5m - (Robo-AO), Keck: II - (NIRC2-LGS), Gemini- - Gillett - - (GNIRS,NIRI), SOAR - The Southern Astrophysical Research Telescope (Goodman spectrograph, TSpec spectrograph, HRCam).
Software References
Astropy, IRAF, TOPCAT (Taylor 2005), Lightkurve (Lightkurve Collaboration et al. 2018).
Files
Reipurth_2024_AJ_168_143.pdf
Additional details
Funding
- National Science Foundation
- AST-0906060
- National Science Foundation
- AST-0960343
- National Science Foundation
- AST-1207891
Dates
- Accepted
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2024-05-10Accepted
- Available
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2024-09-04Published online
Caltech Custom Metadata
- Publication Status
- Published