Astrometry and Precise Radial Velocities Yield a Complete Orbital Solution for the Nearby Eccentric Brown Dwarf LHS 1610 b
Abstract The LHS 1610 system consists of a nearby ( d = 9.7 pc) M5 dwarf hosting a candidate brown dwarf companion in a 10.6 days, eccentric ( e ∼ 0.37) orbit. We confirm this brown dwarf designation and estimate its mass ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow> <mml:mn>49.5</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>3.5</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>4.3</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> M Jup ) and inclination (114.5° <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msubsup> <mml:mrow/> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>10.0</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>7.4</mml:mn> </mml:mrow> </mml:msubsup> </mml:math> ) by combining discovery radial velocities (RVs) from the Tillinghast Reflector Echelle Spectrograph and new RVs from the Habitable-zone Planet Finder with the available Gaia astrometric two-body solution. We highlight a discrepancy between the measurement of the eccentricity from the Gaia two-body solution ( e = 0.52 ± 0.03) and the RV-only solution ( e = 0.3702 ± 0.0003). We discuss possible reasons for this discrepancy, which can be further probed when the Gaia astrometric time series become available as part of Gaia Data Release 4. As a nearby mid-M star hosting a massive short-period companion with a well-characterized orbit, LHS 1610 b is a promising target to look for evidence of sub-Alfvénic interactions and/or auroral emission at optical and radio wavelengths. LHS 1610 has a flare rate (0.28 ± 0.07 flares per day) on the higher end for its rotation period (84 ± 8 days), similar to other mid-M dwarf systems such as Proxima Cen and YZ Ceti that have recent radio detections compatible with star–planet interactions. While available Transiting Exoplanet Survey Satellite photometry is insufficient to determine an orbital phase dependence of the flares, our complete orbital characterization of this system makes it attractive to probe star–companion interactions with additional photometric and radio observations.
Authors
- Eric B. Ford (ORCID: https://orcid.org/0000-0001-6545-639X)
- Simon Albrecht (ORCID: https://orcid.org/0000-0003-1762-8235)
- Joe P. Ninan (ORCID: https://orcid.org/0000-0001-8720-5612)
- J. R. Callingham (ORCID: https://orcid.org/0000-0002-7167-1819)
- Caleb I. Cañas (ORCID: https://orcid.org/0000-0003-4835-0619)
- H. K. Vedantham (ORCID: https://orcid.org/0000-0002-0872-181X)
- Evan Fitzmaurice (ORCID: https://orcid.org/0000-0003-0199-9699)
- Shubham Kanodia (ORCID: https://orcid.org/0000-0001-8401-4300)
- Robert D. Kavanagh (ORCID: https://orcid.org/0000-0002-1486-7188)
- Arpita Roy (ORCID: https://orcid.org/0000-0001-8127-5775)
- Megan Delamer (ORCID: https://orcid.org/0000-0003-1439-2781)
- Paul Robertson (ORCID: https://orcid.org/0000-0003-0149-9678)
- Benjamin Pope (ORCID: https://orcid.org/0000-0003-2595-9114)
- Andrea S. J. Lin (ORCID: https://orcid.org/0000-0002-9082-6337)
- Guđmundur Stefánsson (ORCID: https://orcid.org/0000-0001-7409-5688)
- Jason T. Wright (ORCID: https://orcid.org/0000-0001-6160-5888)
- Marcus L. Marcussen (ORCID: https://orcid.org/0000-0003-2173-0689)
- Lawrence W. Ramsey (ORCID: https://orcid.org/0000-0002-4289-7958)
- Suvrath Mahadevan (ORCID: https://orcid.org/0000-0001-9596-7983)
- William D. Cochran (ORCID: https://orcid.org/0000-0001-9662-3496)
- Joshua N. Winn (ORCID: https://orcid.org/0000-0002-4265-047X)
Institutions
- Tata Institute of Fundamental Research (IN)
- Leiden University (NL)
- Goddard Space Flight Center (US)
- Pennsylvania State University (US)
- The University of Queensland (AU)
- University of Groningen (NL)
- University of Southern Queensland (AU)
- Carnegie Institution for Science (US)
- Princeton University (US)
- University of California, Irvine (US)
- Aarhus University (DK)
- Planetary Systems (United States) (US)
- The University of Texas at Austin (US)
- University of Amsterdam (NL)
- Netherlands Institute for Radio Astronomy (NL)
Publication Details
- Journal
- The Astronomical Journal
- Published
- 2024-09-01
- DOI
- https://doi.org/10.3847/1538-3881/ad57be
- Citations
- 6
- Primary Topic
- Stellar, planetary, and galactic studies
- Type
- article
- Field-Weighted Citation Impact
- 1.99
Funders
- National Science Foundation
- National Aeronautics and Space Administration
- Pennsylvania Space Grant Consortium
- Oak Ridge Associated Universities
- California Institute of Technology
- University of Texas at Austin
- Space Telescope Science Institute
- Heising-Simons Foundation
- NASA Exoplanet Science Institute
- European Space Agency
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek
- Nuclear Safety and Security Commission
- NASA Astrobiology Institute
- Jet Propulsion Laboratory
- Goddard Space Flight Center
- NASA Headquarters
- Astrophysics Division