Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Two accreting protoplanets around the young star PDS 70

Nature Astronomy volume 3, pages 749–754 (2019)Cite this article

Subjects

Abstract

Newly forming protoplanets are expected to create cavities and substructures in young, gas-rich protoplanetary disks1,2,3, but they are difficult to detect as they could be confused with disk features affected by advanced image analysis techniques4,5. Recently, a planet was discovered inside the gap of the transitional disk of the T Tauri star PDS 706,7. Here, we report on the detection of strong Hα emission from two distinct locations in the PDS 70 system, one corresponding to the previously discovered planet PDS 70 b, which confirms the earlier Hα detection8, and another located close to the outer edge of the gap, coinciding with a previously identified bright dust spot in the disk and with a small opening in a ring of molecular emission6,7,9. We identify this second Hα peak as a second protoplanet in the PDS 70 system. The Hα emission spectra of both protoplanets indicate ongoing accretion onto the protoplanets10,11, which appear to be near a 2:1 mean motion resonance. Our observations show that adaptive-optics-assisted, medium-resolution integral field spectroscopy with MUSE12 targeting accretion signatures will be a powerful way to trace ongoing planet formation in transitional disks at different stages of their evolution. Finding more young planetary systems in mean motion resonance would give credibility to the Grand Tack hypothesis in which Jupiter and Saturn migrated in a resonance orbit during the early formation period of our Solar System13.

This is a preview of subscription content, access via your institution

Access options

Buy this article

  • Purchase on Springer Link
  • Instant access to full article PDF
Buy now

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Overview of the PDS 70 system.
Fig. 2: Multi-epoch detection of PDS 70 b and c.
Fig. 3: Composite image of the protoplanetary disk and the two companions.

Similar content being viewed by others

Data availability

The data used in this work are publicly available on the ESO archive (http://archive.eso.org/) under programmes 60.A-9100(K), 095.C-0298(A), 097.C-0206(A) and 097.C-1001(A).

References

  1. Kley, W. & Nelson, R. P. Planet-disk interaction and orbital evolution. Annu. Rev. Astron. Astrophys. 50, 211–249 (2012).

    Article  ADS  Google Scholar 

  2. Zhu, Z., Nelson, R. P., Hartmann, L., Espaillat, C. & Calvet, N. Transitional and pre-transitional disks: gap opening by multiple planets? Astrophys. J. 729, 47 (2011).

    Article  ADS  Google Scholar 

  3. Dodson-Robinson, S. E. & Salyk, C. Transitional disks as signposts of young, multiplanet systems. Astrophys. J. 738, 131 (2011).

    Article  ADS  Google Scholar 

  4. Rameau, J. et al. An optical/near-infrared investigation of HD 100546 b with the gemini planet imager and MagAO. Astrophys. J. 153, 224 (2017).

    Google Scholar 

  5. Huélamo, N. et al. Searching for Hα emitting sources around MWC 758. SPHERE/ZIMPOL high-contrast imaging. Astron. Astrophys. 613, L5 (2018).

    Article  ADS  Google Scholar 

  6. Keppler, M. et al. Discovery of a planetary-mass companion within the gap of the transition disk around PDS 70. Astron. Astrophys. 617, A44 (2018).

    Article  Google Scholar 

  7. Müller, A. et al. Orbital and atmospheric characterization of the planet within the gap of the PDS 70 transition disk. Astron. Astrophys. 617, L2 (2018).

    Article  ADS  Google Scholar 

  8. Wagner, L. et al. Magellan adaptive optics imaging of PDS 70: measuring the mass accretion rate of a young giant planet within a gapped disk. Astrophys. J. 863, L8 (2018).

    Article  ADS  Google Scholar 

  9. Long, Z. C. et al. Differences in the gas and dust distribution in the transitional disk of a Sun-like young star, PDS 70. Astrophys. J. 858, 112 (2018).

    Article  ADS  Google Scholar 

  10. Natta, A. et al. Accretion in brown dwarfs: an infrared view. Astron. Astrophys. 424, 603–612 (2004).

    Article  ADS  Google Scholar 

  11. Rigliaco, E. et al. X-shooter spectroscopy of young stellar objects. I. Mass accretion rates of low-mass T Tauri stars in σ Orionis. Astron. Astrophys. 548, A56 (2012).

    Article  Google Scholar 

  12. Bacon, R. et al. The MUSE second-generation VLT instrument. Proc. SPIE 7735, 773508 (2010).

    Article  Google Scholar 

  13. Walsh, K. et al. A low mass for Mars from Jupiter’s early gas-driven migration. Nature 475, 206–209 (2011).

    Article  ADS  Google Scholar 

  14. Gaia Collaboration The Gaia mission. Astron. Astrophys. 595, A1 (2016).

  15. Gaia Collaboration Gaia data release 2. Summary of the contents and survey properties. Astron. Astrophys. 616, A1 (2018).

  16. Gregorio-Hetem, J. & Hetem, A. Classification of a selected sample of weak T Tauri stars. Mon. Not. R. Astron. Soc. 336, 197–206 (2002).

    Article  ADS  Google Scholar 

  17. Hashimoto, J. et al. Polarimetric imaging of large cavity structures in the pre-transitional protoplanetary disk around PDS 70: observations of the disk. Astrophys. J. 758, L19 (2012).

    Article  ADS  Google Scholar 

  18. Hashimoto, J. et al. The structure of pre-transitional protoplanetary disks. II. Azimuthal asymmetries, different radial distributions of large and small dust grains in PDS 70. Astrophys. J. 799, 43 (2015).

    Article  ADS  Google Scholar 

  19. Pinilla, P. et al. Trapping dust particles in the outer regions of protoplanetary disks. Astron. Astrophys. 538, A114 (2012).

    Article  Google Scholar 

  20. Pinilla, P., Benisty, M. & Birnstiel, T. Ring shaped dust accumulation in transition disks. Astron. Astrophys. 545, A81 (2013).

    Article  Google Scholar 

  21. Edwards, S., Hartigan, P., Ghandour, L. & Andrulis, C. Spectroscopic evidence for magnetospheric accretion in classical T Tauri stars. Astrophys. J. 108, 1056 (1994).

    ADS  Google Scholar 

  22. Reipurth, B., Pedrosa, A. & Lago, M. T. V. T. Hα emission in pre-main sequence stars. I. An atlas of line profiles. Astron. Astrophys. Suppl. 120, 229–256 (1996).

    Article  ADS  Google Scholar 

  23. Armitage, P. J., Livio, M. & Pringle, J. E. Episodic accretion in magnetically layered protoplanetary discs. Mon. Not. R. Astron. Soc. 324, 705–711 (2001).

    Article  ADS  Google Scholar 

  24. Xu, W., Lai, D. & Morbidelli, A. Migration of planets into and out of mean motion resonances in protoplanetary discs: overstability of capture and non-linear eccentricity damping. Mon. Not. R. Astron. Soc. 481, 1538–1549 (2018).

    Article  ADS  Google Scholar 

  25. Nelson, R. P., Papaloizou, J. C. B., Masset, F. & Kley, W. The migration and growth of protoplanets in protostellar discs. Mon. Not. R. Astron. Soc. 318, 18–36 (2000).

    Article  ADS  Google Scholar 

  26. Kley, W., Peitz, J. & Bryden, G. Evolution of planetary systems in resonance. Astron. Astrophys. 414, 735–747 (2004).

    Article  ADS  Google Scholar 

  27. Oberti, S. et al. AOF LTAO mode: reconstruction strategy and first test results. Proc. SPIE 9909, 99091 (2016).

    Google Scholar 

  28. Madec, P. Y. et al. Adaptive optics facility: from an amazing present to a brilliant future. Proc. SPIE 10703, 1070302 (2018).

    Google Scholar 

  29. Weilbacher, P. M. et al. The MUSE data reduction pipeline: status after preliminary acceptance Europe. Proc. Astron. Data Anal. Softw. Syst. XXIII 485, 451 (2014).

    ADS  Google Scholar 

  30. Hoeijmakers, H. J. et al. Medium-resolution integral-field spectroscopy for high-contrast exoplanet imaging. Molecule maps of the β Pictoris system with SINFONI. Astron. Astrophys. 617, A114 (2018).

    Article  Google Scholar 

  31. Pueyo, L. Detection and characterization of exoplanets using projections on Karhunen Loeve eigenimages: forward modeling. Astrophys. J. 824, 117 (2016).

    Article  ADS  Google Scholar 

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

    Article  ADS  Google Scholar 

  33. Vigan, A. et al. Photometric characterization of exoplanets using angular and spectral differential imaging. Mon. Not. R. Astron. Soc. 407, 71–82 (2010).

    Article  ADS  Google Scholar 

  34. Stolker, T. et al. PynPoint: a modular pipeline architecture for processing and analysis of high-contrast imaging data. Astron. Astrophys. 621, A59 (2019).

    Article  Google Scholar 

  35. Hunziker, S., Quanz, S. P., Amara, A. & Meyer, M. R. PCA-based approach for subtracting thermal background emission in high-contrast imaging data. Astron. Astrophys. 611, A23 (2018).

    Article  ADS  Google Scholar 

  36. Marois, C., Lafreniere, D., Doyon, R., Macintosh, B. & Nadeau, D. Angular differential imaging: a powerful high-contrast imaging technique. Astrophys. J. 641, 556–564 (2006).

    Article  ADS  Google Scholar 

  37. Amara, A. & Quanz, S. P. PYNPOINT: an image processing package for finding exoplanets. Mon. Not. R. Astron. Soc. 427, 948–955 (2012).

    Article  ADS  Google Scholar 

  38. Soummer, R. Apodized pupil Lyot coronagraphs for arbitrary telescope apertures. Astrophys. J. Lett. 618, L161–L164 (2004).

    Article  ADS  Google Scholar 

  39. Choquet, É. et al. Archival legacy investigations of circumstellar environments: overview and first results. Proc. SPIE 9143, 914357 (2014).

    Article  Google Scholar 

  40. Smith, B. A. & Terrile, R. J. A circumstellar disk around β Pictoris. Science 226, 1421–1424 (1984).

    Article  ADS  Google Scholar 

  41. Allard, F. et al. The limiting effects of dust in brown dwarf model atmospheres. Astrophys. J. 556, 357–372 (2001).

    Article  ADS  Google Scholar 

Download references

Acknowledgements

This work is based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere under ESO programmes 60.A-9100(K), 095.C-0298(A), 097.C-0206(A) and 097.C-1001(A). A.J.B. and J.d.B. acknowledge support from the European Research Council (ERC) Starting Grant 678194 (FALCONER). I.A.G.S. acknowledges funding from the ERC under the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 694513. R.B. acknowledges support from the ERC advanced grant 339659-MUSICOS. J.B. acknowledges support by FCT/MCTES through national funds by the grant UID/FIS/04434/2019 and through the Investigador FCT contract no. IF/01654/2014/CP1215/CT0003. The authors acknowledge the ESO AOF and Paranal teams for their expertise and support during the commissioning activities.

Author information

Authors and Affiliations

  1. Leiden Observatory, Leiden University, Leiden, The Netherlands

    S. Y. Haffert, A. J. Bohn, J. de Boer, I. A. G. Snellen, J. Brinchmann & C. U. Keller

  2. Instituto de Astrofísica e Ciências do Espaço, Universidade do Porto, CAUP, Porto, Portugal

    J. Brinchmann

  3. Space Telescope Science Institute, Baltimore, MD, USA

    J. H. Girard

  4. Université Grenoble Alpes, CNRS, IPAG, Grenoble, France

    J. H. Girard

  5. CRAL, Observatoire de Lyon, CNRS, Université Lyon 1, Saint Genis Laval, France

    R. Bacon

Authors
  1. S. Y. Haffert
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. A. J. Bohn
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. J. de Boer
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. I. A. G. Snellen
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. J. Brinchmann
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. J. H. Girard
    View author publications

    You can also search for this author in PubMed Google Scholar

  7. C. U. Keller
    View author publications

    You can also search for this author in PubMed Google Scholar

  8. R. Bacon
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

This work made use of the newly commissioned narrow-field mode of MUSE on the VLT that was led by R.B. S.Y.H., J.d.B., J.H.G. and J.B. prepared the observations, which were executed by R.B. and J.B. J.B. reduced the raw data products from MUSE with the ESO MUSE pipeline. S.Y.H. wrote the HRSDI pipeline, processed and analysed the combined data cubes, and performed the astrometry and orbit fitting. A.J.B. reduced the archival SPHERE and NACO data, performed the photometry and astrometry on these datasets and wrote the corresponding sections. I.A.G.S. and C.U.K. supervised the effort of S.Y.H. All authors contributed to key aspects of the manuscript.

Corresponding author

Correspondence to S. Y. Haffert.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Haffert, S.Y., Bohn, A.J., de Boer, J. et al. Two accreting protoplanets around the young star PDS 70. Nat Astron 3, 749–754 (2019). https://doi.org/10.1038/s41550-019-0780-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41550-019-0780-5

This article is cited by

Search

Advanced search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing