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  • Letter
  • Published:

Reduction of the maximum mass-loss rate of OH/IR stars due to unnoticed binary interaction

Nature Astronomy volume 3, pages 408–415 (2019)Cite this article

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An Author Correction to this article was published on 19 March 2019

This article has been updated

Abstract

In 1981, the idea of a superwind that ends the life of cool giant stars was proposed1. Extreme oxygen-rich giants, OH/IR stars, develop superwinds with the highest mass-loss rates known so far, up to a few 10−4 solar masses (M⊙) per year2,3,4,5,6,7,8,9,10,11,12, informing our understanding of the maximum mass-loss rate achieved during the asymptotic giant branch (AGB) phase. A conundrum arises whereby the observationally determined duration of the superwind phase is too short for these stars to lose enough mass to become white dwarfs2,3,4,6,8,9,10. Here we report on the detection of spiral structures around two cornerstone extreme OH/IR stars, OH 26.5 + 0.6 and OH 30.1 − 0.7, thereby identifying them as wide binary systems. Hydrodynamic simulations show that the companion’s gravitational attraction creates an equatorial density enhancement mimicking a short, extreme superwind phase, thereby solving the decades-old conundrum. This discovery restricts the maximum mass-loss rate of AGB stars to around the single-scattering radiation pressure limit of a few 10−5 M⊙ yr−1. This has crucial implications for nucleosynthetic yields, planet survival and the wind-driving mechanism.

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Fig. 1: ALMA 12CO J = 2–1 channel map of OH 26.5 + 0.6.
Fig. 2: ALMA 12CO J = 3–2 channel map of OH 30.1 − 0.7.
Fig. 3: Position–velocity diagrams of the 12CO J = 3–2 emission in OH 26.5 + 0.6 and 12CO J = 2–1 emission in OH 30.1 − 0.7.
Fig. 4: Sketch of the OH 26.5 + 0.6 binary system.

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Code availability

Figures 1–3, and Supplementary Figs. 1 and 2 were made using CASA35. Supplementary Fig. 3 was made using a simple Python script that can be distributed upon request. Supplementary Fig. 4 is based on ballistic trajectory calculations by one of the authors46 solving the equation of motion using a classical fourth-order Runge–Kutta scheme. The code is available for collaboration with I.E.M. upon reasonable request.

Data availability

The ALMA data from proposals 2015.1.00054.S, 2016.1.00005.S and 2016.2.00088.S can be retrieved from the ALMA data archive at http://almascience.eso.org/aq/. The data that support the plots within this paper and other findings of this study are available from the corresponding author upon reasonable request.

Change history

  • 19 March 2019

    In the version of this Letter originally published, the caption of Fig. 2 incorrectly said J = 3–2; it should have said J = 2–1. This has now been corrected.

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Acknowledgements

This paper uses the ALMA data ADS/JAO.ALMA2015.1.00054.S, 2016.1.00005.S and 2016.2.00088.S. ALMA is a partnership of ESO (representing its member states), NSF (United States) and NINS (Japan), together with NRC (Canada) and NSC and ASIAA (Taiwan), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ. This paper makes use of the CASA data reduction package: https://casa.nrao.edu. CASA is developed by an international consortium of scientists based at the National Radio Astronomical Observatory (NRAO), the European Southern Observatory (ESO), the National Astronomical Observatory of Japan (NAOJ), the CSIRO Australia Telescope National Facility (CSIRO/ATNF) and the Netherlands Institute for Radio Astronomy (ASTRON) under the guidance of NRAO. L.D., T.D., W.H. and M.V.d.S. acknowledge support from the ERC consolidator grant 646758 AEROSOL. T.D. acknowledges support from the Fund of Scientific Research Flanders (FWO). D.A.G.-H. acknowledges support provided by the Spanish Ministry of Economy and Competitiveness (MINECO) under grant AYA-2017-88254-P. We acknowledge the help of C. Gottlieb (Harvard University) for his editorial advice on the manuscript.

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Authors and Affiliations

  1. Instituut voor Sterrenkunde, KU Leuven, Leuven, Belgium

    L. Decin, W. Homan, T. Danilovich, A. de Koter, C. Gielen & M. Van de Sande

  2. School of Chemistry, University of Leeds, Leeds, UK

    L. Decin

  3. Astronomical Institute Anton Pannekoek, University of Amsterdam, Amsterdam, The Netherlands

    A. de Koter & L. B. F. M. Waters

  4. Hamburger Sternwarte, Hamburg, Germany

    D. Engels

  5. SRON Netherlands Institute for Space Research, Utrecht, The Netherlands

    L. B. F. M. Waters

  6. Onsala Space Observatory, Department of Space, Earth and Environment, Chalmers University of Technology, Onsala, Sweden

    S. Muller

  7. Instituto de Astrofísica de Canarias, La Laguna, Spain

    D. A. García-Hernández

  8. Departamento de Astrofísica, Universidad de La Laguna (ULL), La Laguna, Spain

    D. A. García-Hernández

  9. E. A. Milne Centre for Astrophysics, Department of Physics & Mathematics, University of Hull, Hull, UK

    R. J. Stancliffe

  10. School of Physics and Astronomy, University of Birmingham, Birmingham, UK

    R. J. Stancliffe

  11. I-BioStat, Universiteit Hasselt, Hasselt, Belgium

    G. Molenberghs

  12. I-BioStat, KU Leuven, Leuven, Belgium

    G. Molenberghs

  13. Department of Astrophysics, University of Vienna, Vienna, Austria

    F. Kerschbaum

  14. Jodrell Bank Centre for Astrophysics, School of Physics & Astronomy, University of Manchester, Manchester, UK

    A. A. Zijlstra

  15. Laboratory for Space Research, University of Hong Kong, Lung Fu Shan, Hong Kong

    A. A. Zijlstra

  16. Centre for Mathematical Plasma-Astrophysics, KU Leuven, Leuven, Belgium

    I. El Mellah

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Contributions

L.D. identified the spiral structure in the ALMA data of OH 26.5 + 0.6 and OH 30.1 − 0.7, performed the full analysis and led the consortium, W.H., T.D. and A.d.K. contributed to the interpretation of the data, D.E., D.A.G.-H. and S.M. proposed the ALMA observations (ALMA proposals 2015.1.00054.S, 2016.1.00005.S and 2016.2.00088.S), S.M. reduced the ALMA data, D.E. did the sample analysis of the extreme OH/IR stars, G.M. gave advice on statistical matters, I.E.M. ran the ballistic simulations, C.G. made Fig. 4 and all authors contributed to the discussion.

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Correspondence to L. Decin.

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Supplementary Information

Supplementary text, Supplementary references, Supplementary Figures 1–4, Supplementary Video 1 caption, Supplementary Video 2 caption.

Supplementary Video 1

Animated 12CO J = 3–2 channel map of star OH 26.5 + 0.6.

Supplementary Video 2

Animated 12CO J = 2–1 channel map of star OH 30.1-0.7.

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Decin, L., Homan, W., Danilovich, T. et al. Reduction of the maximum mass-loss rate of OH/IR stars due to unnoticed binary interaction. Nat Astron 3, 408–415 (2019). https://doi.org/10.1038/s41550-019-0703-5

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