The GRAVITY young stellar object survey

Astronomy and Astrophysics, vol. 655, pp. A334

Abstract

Context . Protoplanetary disks around young Sun-like stars are the cradles of the vast majority of detected exoplanets. Probing these disks at multiple spatial scales is key to uncovering how planets form. The inner astronomical unit, the star-disk interaction region, is of utmost importance because most detected exoplanets occupy this zone. Aims . We aim to spatially and spectrally resolve the inner disk and star-disk interaction region of the M0.3 T Tauri star DO Tau by combining two complementary techniques. Methods . We used high-resolution near-infrared spectra from CFHT/SPIRou to constrain the magnetospheric star-disk interaction process and optical long-baseline interferometry with ESO VLTI/GRAVITY to determine the sizes of the K-band continuum and Br γ line emitting regions. From the SPIRou spectra, we measured the veiling in the YJHK bands along with the equivalent widths of the HeI λ 1083, Paβ, and Br γ emission lines, from which we estimated the mass accretion rate. We were able to monitor the time variability of these quantities thanks to our long-sequence of observations over about 40 days. We fit the GRAVITY visibilities in the continuum and the differential quantities in the line with geometrical models to obtain the orientation and the size of the inner disk as well as the size and the on-sky displacement of the Br γ emitting region. Results . We derived a mass accretion rate of ∼10 −8 −10 −7 M ⊙ yr −1 , which confirms that this ∼0.5 M ⊙ star is a strong accretor. The HI and HeI lines exhibit strong variability on a daily timescale, consistent with the burster classification of DO Tau derived from its K2 light curve. We report a periodic modulation of the intensity of the redshifted high-velocity wings of the Br γ line profile. The modulation occurs at the rotational period of the star (5.128 d), which suggests the existence of corotating magnetospheric funnel flows. We derived an upper limit of 0.35 on the ratio between the magnetospheric truncation radius and the disk corotation radius, indicative of an ordered unstable accretion regime. The size of the Br γ line emitting region obtained from GRAVITY is quite small ( R Brγ = 0.011 au ∼ 1.3 R * ), and it is much smaller than the K-band continuum emitting region ( R K = 0.09 au ∼ 11 R * ). Such a compact Br γ emission region suggests that most of the line flux originates from the magnetospheric accretion region and/or from an inner wind close to the magnetosphere-disk interface. The on-sky displacements of the blue and red Br γ line velocity channels suggest a rotation pattern of the emitting gas, as they appear to be nearly aligned along the position angle of the disk. The inclination we derived for the inner disk (∼45-55°) differs from that of the outer disk inferred from the ALMA continuum (∼30°). This points toward a misalignment or warp of the outer disk that may originate from the suspected past encounter with the neighboring HV Tau system. Conclusions . Based on combining high-resolution spectroscopy and long baseline interferometry, we find that the T Tauri star DO Tau appears to be a strong accretor undergoing magnetospheric accretion in an ordered unstable regime, with a Br γ line emitting region as compact (∼0.01 au) as the size of its magnetosphere.

Authors 33

1. K. Perraut

   Centre National de la Recherche Scientifique · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

   Affiliation as printed

   Univ. Grenoble Alpes, CNRS, IPAG

   Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France

2. Jérôme Bouvier

   Centre National de la Recherche Scientifique · University of Cologne · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

   Affiliation as printed

   Univ. Grenoble Alpes, CNRS, IPAG

   I. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937, Köln, Germany

3. A. P. Sousa

   Centre National de la Recherche Scientifique · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

   Affiliation as printed

   Univ. Grenoble Alpes, CNRS, IPAG

   Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France

4. E. Alécian

   Centre National de la Recherche Scientifique · Institut de Planétologie et d'Astrophysique de Grenoble · University of Chile · Université Grenoble Alpes

   Affiliation as printed

   Univ. Grenoble Alpes, CNRS, IPAG

   Unidad Mixta Internacional Franco-Chilena de Astronomía (CNRS UMI 3386), Departamento de Astronomía, Universidad de Chile, Camino El Observatorio 1515, Las Condes, Santiago, Chile

   Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France

5. Y.-I. Bouarour

   Centre National de la Recherche Scientifique · Dublin Institute For Advanced Studies · Astronomical Observatory of Capodimonte · Institut de Planétologie et d'Astrophysique de Grenoble · National Institute for Astrophysics · Université Grenoble Alpes

   Affiliation as printed

   Univ. Grenoble Alpes, CNRS, IPAG

   Dublin Institute for Advanced Studies, 31 Fitzwilliam Place, D02, XF86 Dublin, Ireland

   INAF – Osservatorio Astronomico di Capodimonte, via Moiariello 16, 80131 Napoli, Italy

6. Lucas Labadie

   Centre National de la Recherche Scientifique · University of Cologne · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Paris Cité · Laboratoire d’études spatiales et d’instrumentation en astrophysique

   Affiliation as printed

   I. Physikalisches Institut, Universität zu Köln

   LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France

7. J. Sánchez-Bermúdez

   Max Planck Institute for Extraterrestrial Physics · Universidad Nacional Autónoma de México

   Affiliation as printed

   Instituto de Astronomía, Universidad Nacional Autónoma de México

   Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

8. A. Amorim

   University of Lisbon · LIP - Laboratory of Instrumentation and Experimental Particle Physics · Max Planck Institute for Extraterrestrial Physics

   Affiliation as printed

   LIP, Laboratory for Instrumentation and Experimental Particle Physics

   Universidade de Lisboa—Faculdade de Ciências

   Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

9. Y. Clénet

   Centre National de la Recherche Scientifique · Universidade do Porto · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université · Instituto Superior Técnico · Centro de Astrofísica e Gravitação

   Affiliation as printed

   LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité

   CENTRA, Centro de Astrofísica e Gravitação, Instituto Superior Técnico, Avenida Rovisco Pais 1, 1049 Lisboa, Portugal

   Universidade do Porto, Faculdade de Engenharia, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal

10. R. Davies

    Centre National de la Recherche Scientifique · Max Planck Society · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Paris Cité · Max Planck Institute for Extraterrestrial Physics · Laboratoire d’études spatiales et d’instrumentation en astrophysique

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

    LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France

11. R. Dembet

    Centre National de la Recherche Scientifique · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

12. Antonia Drescher

    Centre National de la Recherche Scientifique · Max Planck Institute for Extraterrestrial Physics · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

    Affiliation as printed

    Univ. Grenoble Alpes, CNRS, IPAG

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

13. A. Eckart

    University of Cologne

    Affiliation as printed

    I. Physikalisches Institut, Universität zu Köln

    I. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937, Köln, Germany

14. F. Eisenhauer

    Centre National de la Recherche Scientifique · Max Planck Society · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Paris Cité · Max Planck Institute for Extraterrestrial Physics · Laboratoire d’études spatiales et d’instrumentation en astrophysique

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

    LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France

15. N. M. Förster Schreiber

    Centre National de la Recherche Scientifique · Max Planck Society · Max Planck Institute for Extraterrestrial Physics · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

    Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France

16. Eric Gendron

    Centre National de la Recherche Scientifique · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université · Sorbonne Paris Cité · Laboratoire d’études spatiales et d’instrumentation en astrophysique

    Affiliation as printed

    LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité

    LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France

17. R. Genzel

    Centre National de la Recherche Scientifique · Max Planck Society · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Paris Cité · Max Planck Institute for Extraterrestrial Physics · Laboratoire d’études spatiales et d’instrumentation en astrophysique

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

    LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France

18. S. Gillessen

    Centre National de la Recherche Scientifique · Max Planck Society · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Paris Cité · Max Planck Institute for Extraterrestrial Physics · Laboratoire d’études spatiales et d’instrumentation en astrophysique

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

    LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France

19. Thomas K. Henning

    Centre National de la Recherche Scientifique · Max Planck Institute for Astronomy · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

    Affiliation as printed

    Max Planck Institute for Astronomy

    Univ. Grenoble Alpes, CNRS, IPAG, 38000 Grenoble, France

20. P. Kervella

    Centre National de la Recherche Scientifique · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

21. S. Lacour

    Centre National de la Recherche Scientifique · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université · Sorbonne Paris Cité · Laboratoire d’études spatiales et d’instrumentation en astrophysique

    Affiliation as printed

    LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité

    LESIA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universités, UPMC Univ. Paris 06, Univ. Paris Diderot, Sorbonne Paris Cité, France

22. V. Lapeyrère

    Centre National de la Recherche Scientifique · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université · Max Planck Institute for Astronomy

    Affiliation as printed

    LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité

    Max Planck Institute for Astronomy, Königstuhl 17, 69117 Heidelberg, Germany

23. J.-B. Le Bouquin

    Centre National de la Recherche Scientifique · Max Planck Institute for Extraterrestrial Physics · Institut de Planétologie et d'Astrophysique de Grenoble · Université Grenoble Alpes

    Affiliation as printed

    Univ. Grenoble Alpes, CNRS, IPAG

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

24. Dieter Lutz

    Max Planck Society · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

25. Thomas Ott

    Max Planck Society · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

26. T. Paumard

    Centre National de la Recherche Scientifique · University of Cologne · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université

    Affiliation as printed

    LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité

    I. Physikalisches Institut, Universität zu Köln, Zülpicher Strasse 77, 50937, Köln, Germany

27. Guy S. Perrin

    Centre National de la Recherche Scientifique · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse, 85741 Garching bei München, Germany

28. J. Shangguan

    Max Planck Society · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

29. Thomas Shimizu

    Max Planck Society · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

30. C. Straubmeier

    University of Cologne

    Affiliation as printed

    I. Physikalisches Institut, Universität zu Köln

31. E. Sturm

    Max Planck Society · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

32. Linda J. Tacconi

    Max Planck Society · Max Planck Institute for Extraterrestrial Physics

    Affiliation as printed

    Max Planck Institute for Extraterrestrial Physics, Giessenbachstrasse

33. Frederic H. Vincent

    Centre National de la Recherche Scientifique · Université Paris Cité · Université Paris Sciences et Lettres · Observatoire de Paris · Sorbonne Université

    Affiliation as printed

    LIRA, Observatoire de Paris, Université PSL, CNRS, Sorbonne Université, Université Paris Cité