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A circumbinary protoplanetary disk in a polar configuration

A Publisher Correction to this article was published on 07 February 2019

This article has been updated


Nearly all young stars are initially surrounded by ‘protoplanetary’ disks of gas and dust, and in the case of single stars at least 30% of these disks go on to form planets1. The process of protoplanetary disk formation can result in initial misalignments, where the disk orbital plane is different from the stellar equator in single-star systems, or different from the binary orbital plane in systems with two stars2. A quirk of the dynamics means that initially misaligned ‘circumbinary’ disks—those that surround two stars—are predicted to evolve to one of two possible stable configurations: one where the disk and binary orbital planes are coplanar and one where they are perpendicular (a ‘polar’ configuration)3,4,5. Previous work has found coplanar circumbinary disks6, but no polar examples were known until now. Here, we report the first discovery of a protoplanetary circumbinary disk in the polar configuration, supporting the predictions that such disks should exist. The disk shows some characteristics that are similar to disks around single stars, and that are attributed to dust growth. Thus, the first stages of planet formation appear able to proceed in polar circumbinary disks.

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Fig. 1: ALMA 1.3 mm continuum image of the HD 98800 dust disk, showing a narrow dust ring 3.5 au in radius that is 2 au wide.
Fig. 2: Carbon monoxide gas velocity map.
Fig. 3: Three-dimensional sketch of the polar configuration.

Data availability

The ALMA data used in this study are available in the ALMA Science Archive (project code 2017.1.00350.S). Post-processing, modelling and other code used in this study are available on GitHub at Post-processed 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

  • 07 February 2019

    In the version of this Letter originally published, the Author Contributions section was mistakenly omitted, and should have read: “G.M.K. conceived the project, analysed the data, carried out the modelling and wrote the manuscript. L.M. contributed gas calculations and provided advice on self-calibration. B.M.Y. set up and ran the n-body simulations. D.P. provided advice on running the smoothed particle hydrodynamics simulations. All co-authors provided input on the manuscript.” In addition, in the fourth paragraph, due to a typographical error the value of the ascending node was incorrect as 289 ± 1° and should have been 337.6 ± 2.4°. These errors have now been corrected.


  1. 1.

    Zhu, W., Petrovich, C., Wu, Y., Dong, S. & Xie, J. About 30% of Sun-like stars have Kepler-like planetary systems: a study of their intrinsic architecture. Astrophys. J. 860, 101 (2018).

    ADS  Article  Google Scholar 

  2. 2.

    Bate, M. R. On the diversity and statistical properties of protostellar discs. Mon. Not. R. Astron. Soc. 475, 5618–5658 (2018).

    ADS  Article  Google Scholar 

  3. 3.

    Aly, H., Dehnen, W., Nixon, C. & King, A. Misaligned gas discs around eccentric black hole binaries and implications for the final-parsec problem. Mon. Not. R. Astron. Soc. 449, 65–76 (2015).

    ADS  Article  Google Scholar 

  4. 4.

    Martin, R. G. & Lubow, S. H. Polar alignment of a protoplanetary disk around an eccentric binary. Astrophys. J. Lett. 835, L28 (2017).

    ADS  Article  Google Scholar 

  5. 5.

    Zanazzi, J. J. & Lai, D. Inclination evolution of protoplanetary discs around eccentric binaries. Mon. Not. R. Astron. Soc. 473, 603–615 (2018).

    ADS  Article  Google Scholar 

  6. 6.

    Rodriguez, D. R., Kastner, J. H., Wilner, D. & Qi, C. Imaging the molecular disk orbiting the twin young suns of V4046 Sgr. Astrophys. J. 720, 1684–1690 (2010).

    ADS  Article  Google Scholar 

  7. 7.

    Brinch, C., Jørgensen, J. K., Hogerheijde, M. R., Nelson, R. P. & Gressel, O. Misaligned disks in the binary protostar IRS 43. Astrophys. J. Lett. 830, L16 (2016).

    ADS  Article  Google Scholar 

  8. 8.

    Farago, F. & Laskar, J. High-inclination orbits in the secular quadrupolar three-body problem. Mon. Not. R. Astron. Soc. 401, 1189–1198 (2010).

    ADS  Article  Google Scholar 

  9. 9.

    Foucart, F. & Lai, D. Assembly of protoplanetary disks and inclinations of circumbinary planets. Astrophys. J. 764, 106 (2013).

    ADS  Article  Google Scholar 

  10. 10.

    Lubow, S. H. & Martin, R. G. Linear analysis of the evolution of nearly polar low-mass circumbinary discs.Mon. Not. R. Astron. Soc. 473, 3733–3746 (2018).

    ADS  Article  Google Scholar 

  11. 11.

    Martin, R. G. & Lubow, S. H. Polar alignment of a protoplanetary disc around an eccentric binary—II. Effect of binary and disc parameters. Mon. Not. R. Astron. Soc. 479, 1297–1308 (2018).

    ADS  Article  Google Scholar 

  12. 12.

    Haisch, K. E. Jr., Lada, E. A. & Lada, C. J. Disk frequencies and lifetimes in young clusters. Astrophys. J. Lett. 553, L153–L156 (2001).

    ADS  Article  Google Scholar 

  13. 13.

    Kennedy, G. M. et al. 99 Herculis: host to a circumbinary polar-ring debris disc. Mon. Not. R. Astron. Soc 421, 2264–2276 (2012).

    ADS  Article  Google Scholar 

  14. 14.

    Van Leeuwen, F. Validation of the new Hipparcos reduction. Astron. Astrophys. 474, 653–664 (2007).

    ADS  Article  Google Scholar 

  15. 15.

    Kastner, J. H., Zuckerman, B., Weintraub, D. A. & Forveille, T. X-ray and molecular emission from the nearest region of recent star formation. Science 277, 67–71 (1997).

    ADS  Article  Google Scholar 

  16. 16.

    Barrado Y Navascués, D. On the age of the TW Hydrae association and 2M1207334-393254. Astron. Astrophys. 459, 511–518 (2006).

    ADS  Article  Google Scholar 

  17. 17.

    Boden, A. F. et al. Dynamical masses for low-mass pre-main-sequence stars: a preliminary physical orbit for HD 98800 B. Astrophys. J. 635, 442–451 (2005).

    ADS  Article  Google Scholar 

  18. 18.

    Walker, H. J. & Wolstencroft, R. D. Cool circumstellar matter around nearby main-sequence stars. Publ. Astron. Soc. Pac. 100, 1509–1521 (1988).

    ADS  Article  Google Scholar 

  19. 19.

    Akeson, R. L. et al. The circumbinary disk of HD 98800B: evidence for disk warping. Astrophys. J. 670, 1240–1246 (2007).

    ADS  Article  Google Scholar 

  20. 20.

    Andrews, S. M. et al. Truncated disks in TW Hya association multiple star systems. Astrophys. J. 710, 462–469 (2010).

    ADS  Article  Google Scholar 

  21. 21.

    Ribas, Á., Macías, E., Espaillat, C. C. & Duchêne, G. Long-lived protoplanetary disks in multiple systems: the VLA view of HD 98800. Astrophys. J. 865, 77 (2018)..

  22. 22.

    Furlan, E. et al. HD 98800: a 10 Myr old transition disk. Astrophys. J. 664, 1176–1184 (2007).

    ADS  Article  Google Scholar 

  23. 23.

    Wyatt, M. C. et al. Transience of hot dust around Sun-like stars. Astrophys. J. 658, 569–583 (2007).

    ADS  Article  Google Scholar 

  24. 24.

    Riviere-Marichalar, P. et al. Gas and dust in the TW Hydrae association as seen by the Herschel Space Observatory. Astron. Astrophys. 555, A67 (2013).

    Article  Google Scholar 

  25. 25.

    Yang, H. et al. A far-ultraviolet atlas of low-resolution Hubble Space Telescope spectra of T Tauri stars. Astrophys. J. 744, 121 (2012).

    ADS  Article  Google Scholar 

  26. 26.

    Andrews, S. M. et al. The TW Hya disk at 870 μm: comparison of CO and dust radial structures. Astrophys. J. 744, 162 (2012).

    ADS  Article  Google Scholar 

  27. 27.

    Facchini, S., Birnstiel, T., Bruderer, S. & van Dishoeck, E. F. Different dust and gas radial extents in protoplanetary disks: consistent models of grain growth and CO emission. Astron. Astrophys. 605, A16 (2017).

    ADS  Article  Google Scholar 

  28. 28.

    Raghavan, D. et al. A survey of stellar families: multiplicity of solar-type stars. Astrophys. J. Suppl. Ser. 190, 1–42 (2010).

    ADS  Article  Google Scholar 

  29. 29.

    Muñoz, D. J. & Lai, D. Survival of planets around shrinking stellar binaries.Proc. Natl Acad. Sci. USA 112, 9264–9269 (2015).

    ADS  Article  Google Scholar 

  30. 30.

    Martin, D. V., Mazeh, T. & Fabrycky, D. C. No circumbinary planets transiting the tightest Kepler binaries—apossible fingerprint of a third star. Mon. Not. R. Astron. Soc. 453, 3554–3567 (2015).

    ADS  Article  Google Scholar 

  31. 31.

    Kostov, V. B. et al. Kepler-1647b: the largest and longest-period Kepler transiting circumbinary planet. Astrophys. J. 827, 86 (2016).

    ADS  Article  Google Scholar 

  32. 32.

    Guilloteau, S., Dutrey, A., Piétu, V. & Boehler, Y. A dual-frequency sub-arcsecond study of proto-planetary disks at mm wavelengths: first evidence for radial variations of the dust properties. Astron. Astrophys. 529, A105 (2011).

    ADS  Article  Google Scholar 

  33. 33.

    Walker, H. J. & Butner, H. M. Follow-up observations of β-pic-like stars. Astrophys. Space Sci. 224, 389–393 (1995).

    ADS  Article  Google Scholar 

  34. 34.

    Foreman-Mackey, D., Hogg, D. W., Lang, D. & Goodman, J. emcee: the MCMC hammer. Publ. Astron. Soc. Pac. 125, 306–312 (2013).

    ADS  Article  Google Scholar 

  35. 35.

    Tazzari, M., Beaujean, F. & Testi, L. GALARIO: a GPU accelerated library for analysing radio interferometerobservations. Mon. Not. R. Astron. Soc. 476, 4527–4542 (2018).

    ADS  Article  Google Scholar 

  36. 36.

    Soderblom, D. R. et al. HD 98800: a unique stellar system of Post-T Tauri stars. Astrophys. J. 498, 385–393 (1998).

    ADS  Article  Google Scholar 

  37. 37.

    Tokovinin, A. A. The visual orbit of HD 98800. Astron. Lett. 25, 669–671 (1999).

    ADS  Google Scholar 

  38. 38.

    Rein, H. & Liu, S.-F. REBOUND: an open-source multi-purpose N-body code for collisional dynamics. Astron. Astrophys. 537, A128 (2012).

    ADS  Article  Google Scholar 

  39. 39.

    Doolin, S. & Blundell, K. M. The dynamics and stability of circumbinary orbits.Mon. Not. R. Astron. Soc. 418, 2656–2668 (2011).

    ADS  Article  Google Scholar 

  40. 40.

    Rein, H. & Tamayo, D. WHFAST: a fast and unbiased implementation of a symplectic Wisdom–Holman integrator for long-term gravitational simulations. Mon. Not. R. Astron. Soc. 452, 376–388 (2015).

    ADS  Article  Google Scholar 

  41. 41.

    Price, D. J. et al. Phantom: a smoothed particle hydrodynamics and magnetohydrodynamics code for astrophysics. Publ. Astron. Soc. Aust. 35, e031 (2018).

    ADS  Article  Google Scholar 

  42. 42.

    Price, D. J. splash: an interactive visualisation tool for smoothed particle hydrodynamics simulations. Publ. Astron. Soc. Aust. 24, 159–173 (2007).

    ADS  Article  Google Scholar 

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G.M.K. is supported by the Royal Society as a Royal Society University Research Fellow. L.M. acknowledges support from the Smithsonian Institution as a Submillimeter Array Fellow. O.P. is supported by the Royal Society Dorothy Hodgkin Fellowship. S.F. acknowledges an ESO Fellowship. We thank A. Ribas for sharing the Very Large Array image of HD 98800. This paper makes use of the following ALMA data: ADS/JAO.ALMA#2017.1.00350.S. ALMA is a partnership of the ESO (representing its member states), NSF (United States) and NINS (Japan), together with NRC (Canada), MOST and ASIAA (Taiwan), and KASI (Republic of Korea), in cooperation with the Republic of Chile. The Joint ALMA Observatory is operated by ESO, AUI/NRAO and NAOJ.

Author information




G.M.K. conceived the project, analysed the data, carried out the modelling and wrote the manuscript. L.M. contributed gas calculations and provided advice on self-calibration. B.M.Y. set up and ran the n-body simulations. D.P. provided advice on running the smoothed particle hydrodynamics simulations. All co-authors provided input on the manuscript.

Corresponding author

Correspondence to Grant M. Kennedy.

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Supplementary Information

Supplementary text, Supplementary references, Supplementary Tables 1–3, Supplementary Figures 1–7

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Kennedy, G.M., Matrà, L., Facchini, S. et al. A circumbinary protoplanetary disk in a polar configuration. Nat Astron 3, 230–235 (2019).

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