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Publication . Article . Preprint . 2019 . Embargo end date: 04 Sep 2019

Tidal Interactions between Binary Stars Can Drive Lithium Production in Low-mass Red Giants

Casey, Andrew; Ho, AYQ; Ness, M; Hogg, DW; Rix, HW; Angelou, GC; Hekker, S; +6 Authors
Open Access  
Published: 01 Aug 2019
Publisher: Apollo - University of Cambridge Repository
Abstract
Theoretical models of stellar evolution predict that most of the lithium inside a star is destroyed as the star becomes a red giant. However, observations reveal that about 1% of red giants are peculiarly rich in lithium, often exceeding the amount in the interstellar medium or predicted from the Big Bang. With only about 150 lithium-rich giants discovered in the past four decades, and no distinguishing properties other than lithium enhancement, the origin of lithium-rich giant stars is one of the oldest problems in stellar astrophysics. Here we report the discovery of 2,330 low-mass (1 to 3$\,M_\odot$) lithium-rich giant stars, which we argue are consistent with internal lithium production that is driven by tidal spin-up by a binary companion. Our sample reveals that most lithium-rich giants have helium-burning cores ($80^{+7}_{-6}\%$), and that the frequency of lithium-rich giants rises with increasing stellar metallicity. We find that while planet accretion may explain some lithium-rich giants, it cannot account for the majority that have helium-burning cores. We rule out most other proposed explanations as the primary mechanism for lithium-rich giants, including all stages related to single star evolution. Our analysis shows that giants remain lithium-rich for only about two million years. A prediction from this lithium depletion timescale is that most lithium-rich giants with a helium-burning core have a binary companion.
Comment: ApJ accepted. Catalog of 2,330 lithium-rich giants available at https://zenodo.org/record/3515777
Subjects by Vocabulary

arXiv: Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics Astrophysics::Galaxy Astrophysics Physics::Atomic Physics Astrophysics::Cosmology and Extragalactic Astrophysics Physics::Optics

Microsoft Academic Graph classification: Planet Giant star Metallicity Stellar evolution Astrophysics Binary star Red giant Physics Interstellar medium Accretion (astrophysics)

Subjects

general [binaries], abundances [stars], low-mass [stars], CARBON, CIRCULATION, ABUNDANCES, EVOLUTION, NITROGEN, STELLAR, SEARCH, RGB, Space and Planetary Science, Astronomy and Astrophysics, Astrophysics - Solar and Stellar Astrophysics

73 references, page 1 of 8

Abolfathi, B., Aguado, D. S., Aguilar, G., et al. 2018, The Astrophysical Journal Supplement Series, 235, 42, doi: 10.3847/1538-4365/aa9e8a

Adamow, M., Niedzielski, A., Kowalik, K., et al. 2018, A&A, 613, A47, doi: 10.1051/0004-6361/201732161

Adamow, M., Niedzielski, A., Villaver, E., Nowak, G., & Wolszczan, A. 2012, ApJL, 754, L15, doi: 10.1088/2041-8205/754/1/L15

Adamow, M., Niedzielski, A., Villaver, E., et al. 2015, A&A, 581, A94, doi: 10.1051/0004-6361/201526582

Adamow, M., Niedzielski, A., Villaver, E., Wolszczan, A., & Nowak, G. 2014, A&A, 569, A55, doi: 10.1051/0004-6361/201423400

Anderson, L., Hogg, D. W., Leistedt, B., Price-Whelan, A. M., & Bovy, J. 2018, AJ, 156, 145, doi: 10.3847/1538-3881/aad7bf

Andrievsky, S. M., Gorlova, N. I., Klochkova, V. G., Kovtyukh, V. V., & Panchuk, V. E. 1999, Astronomische Nachrichten, 320, 35

Astropy Collaboration, Robitaille, T. P., Tollerud, E. J., et al. 2013, A&A, 558, A33, doi: 10.1051/0004-6361/201322068

Astropy Collaboration, Price-Whelan, A. M., Sipocz, B. M., et al. 2018, AJ, 156, 123, doi: 10.3847/1538-3881/aabc4f

Blanco-Cuaresma, S., Soubiran, C., Heiter, U., & Jofre, P. 2014, Astronomy & Astrophysics, 569, A111, doi: 10.1051/0004-6361/201423945

Funded byView all
EC| STELLARAGES
Project
STELLARAGES
Accurate ages of stars
  • Funder: European Commission (EC)
  • Project Code: 338251
  • Funding stream: FP7 | SP2 | ERC
,
NSF| PIRE: GROWTH: Global Relay of Observatories Watching Transients Happen
Project
  • Funder: National Science Foundation (NSF)
  • Project Code: 1545949
,
EC| MW-DISK
Project
MW-DISK
How the Milky Way Built Its Disk
  • Funder: European Commission (EC)
  • Project Code: 321035
  • Funding stream: FP7 | SP2 | ERC
,
ARC| Discovery Projects - Grant ID: DP160100637
Project
  • Funder: Australian Research Council (ARC) (ARC)
  • Project Code: DP160100637
  • Funding stream: Discovery Projects
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