The formation of gaseous giant planets is thought to occur in the first few million years after stellar birth. Models1 predict that the process produces a deep gap in the dust component (shallower in the gas2,3,4). Infrared observations of the disk around the young star HD 142527 (at a distance of about 140 parsecs from Earth) found an inner disk about 10 astronomical units (au) in radius5 (1 au is the Earth–Sun distance), surrounded by a particularly large gap6 and a disrupted7 outer disk beyond 140 au. This disruption is indicative of a perturbing planetary-mass body at about 90 au. Radio observations8,9 indicate that the bulk mass is molecular and lies in the outer disk, whose continuum emission has a horseshoe morphology8. The high stellar accretion rate10 would deplete the inner disk11 in less than one year, and to sustain the observed accretion matter must therefore flow from the outer disk and cross the gap. In dynamical models, the putative protoplanets channel outer-disk material into gap-crossing bridges that feed stellar accretion through the inner disk12. Here we report observations of diffuse CO gas inside the gap, with denser HCO+ gas along gap-crossing filaments. The estimated flow rate of the gas is in the range of 7 × 10−9 to 2 × 10−7 solar masses per year, which is sufficient to maintain accretion onto the star at the present rate.
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Lubow, S. H. & D’Angelo, G. Gas flow across gaps in protoplanetary disks. Astrophys. J. 641, 526–533 (2006)
Fouchet, L., Gonzalez, J.-F. & Maddison, S. T. Planet gaps in the dust layer of 3D protoplanetary disks. I. Hydrodynamical simulations of T Tauri disks. Astron. Astrophys. 518, A16 (2010)
Ayliffe, B. A., Laibe, G., Price, D. J. & Bate, M. R. On the accumulation of planetesimals near disc gaps created by protoplanets. Mon. Not. R. Astron. Soc. 423, 1450–1462 (2012)
Zhu, Z., Nelson, R. P., Hartmann, L., Espaillat, C. & Calvet, N. Transitional and pretransitional disks: gap opening by multiple planets? Astrophys. J. 729, 47–58 (2011)
van Boekel, R. et al. The building blocks of planets within the ‘terrestrial’ region of protoplanetary disks. Nature 432, 479–482 (2004)
Fukagawa, M. et al. Near-infrared images of protoplanetary disk surrounding HD 142527. Astrophys. J. 636, L153–L156 (2006)
Casassus, S. et al. The dynamically disrupted gap in HD 142527. Astrophys. J. 754, L31–L35 (2012)
Ohashi, N. Observational signature of planet formation: the ALMA view. Astrophys. Space Sci. 313, 101–107 (2008)
Öberg, K. I. et al. Disk imaging survey of chemistry with SMA. II. Southern sky protoplanetary disk data and full sample statistics. Astrophys. J. 734, 98–109 (2011)
Garcia Lopez, R., Natta, A., Testi, L. & Habart, E. Accretion rates in Herbig Ae stars. Astron. Astrophys. 459, 837–842 (2006)
Verhoeff, A. P. et al. The complex circumstellar environment of HD 142527. Astron. Astrophys. 528, A91–A103 (2011)
Dodson-Robinson, S. E. & Salyk, C. Transitional disks as signposts of young, multiplanet systems. Astrophys. J. 738, 131–145 (2011)
Fujiwara, H. et al. The asymmetric thermal emission of the protoplanetary disk surrounding HD 142527 seen by Subaru/COMICS. Astrophys. J. 644, L133–L136 (2006)
Lyo, A.-R., Ohashi, N., Qi, C., Wilner, D. J. & Su, Y.-N. Millimeter observations of the transition disk around HD 135344B (SAO 206462). Astron. J. 142, 151–160 (2011)
Mathews, G. S., Williams, J. P. & Ménard, F. 880 µm imaging of a transitional disk in Upper Scorpius: holdover from the era of giant planet formation? Astrophys. J. 753, 59–70 (2012)
Tatulli, E. et al. Constraining the wind launching region in Herbig Ae stars: AMBER/VLTI spectroscopy of HD 104237. Astron. Astrophys. 464, 55–58 (2007)
Kraus, S. et al. The origin of hydrogen line emission for five Herbig Ae/Be stars spatially resolved by VLTI/AMBER spectro-interferometry. Astron. Astrophys. 489, 1157–1173 (2008)
Eisner, J. A. et al. Spatially and spectrally resolved hydrogen gas within 0.1 AU of T Tauri and Herbig Ae/Be Stars. Astrophys. J. 718, 774–794 (2010)
Carr, J. S., Mathieu, R. D. & Najita, J. R. Evidence for residual material in accretion disk gaps: CO fundamental emission from the T Tauri spectroscopic binary DQ Tauri. Astrophys. J. 551, 454–460 (2001)
Najita, J., Carr, J. S. & Mathieu, R. D. Gas in the terrestrial planet region of disks: CO fundamental emission from T Tauri Stars. Astrophys. J. 589, 931–952 (2003)
Acke, B. & van den Ancker, M. E. Resolving the disk rotation of HD 97048 and HD 100546 in the [O I] 6300 Å line: evidence for a giant planet orbiting HD 100546. Astron. Astrophys. 449, 267–279 (2006)
van der Plas, G. et al. The structure of protoplanetary disks surrounding three young intermediate mass stars. I. Resolving the disk rotation in the [OI] 6300 Å line. Astron. Astrophys. 485, 487–495 (2008)
Salyk, C., Blake, G. A., Boogert, A. C. A. & Brown, J. M. High-resolution 5 µm spectroscopy of transitional disks. Astrophys. J. 699, 330–347 (2009)
Pontoppidan, K. M. et al. Spectroastrometric imaging of molecular gas within protoplanetary disk gaps. Astrophys. J. 684, 1323–1329 (2008)
van der Plas, G. et al. Evidence for CO depletion in the inner regions of gas-rich protoplanetary disks. Astron. Astrophys. 500, 1137–1141 (2009)
Pontoppidan, K. M., Blake, G. A. & Smette, A. The structure and dynamics of molecular gas in planet-forming zones: a CRIRES spectro-astrometric survey. Astrophys. J. 733, 84–100 (2011)
Sacco, G. G. et al. High-resolution Spectroscopy of Ne II emission from young stellar objects. Astrophys. J. 747, 142 (2012)
Piétu, V., Gueth, F., Hily-Blant, P., Schuster, K.-F. & Pety, J. High resolution imaging of the GG Tauri system at 267 GHz. Astron. Astrophys. 528, A81–A95 (2011)
Beck, T. L. et al. Circumbinary gas accretion onto a central binary: infrared molecular hydrogen emission from GG Tau A. Astrophys. J. 754, 72–77 (2012)
Regály, Z., Juhász, A., Sándor, Z. & Dullemond, C. P. Possible planet-forming regions on submillimetre images. Mon. Not. R. Astron. Soc. 419, 1701–1712 (2012)
This paper makes use of the following ALMA data: ADS/JAO.ALMA#2011.0.00465.S. ALMA is a partnership of the ESO, NSF, NINS, NRC, NSC and ASIAA. The Joint ALMA Observatory is operated by the ESO, AUI/NRAO and NAOJ. This work was also based on observations obtained at the Gemini Observatory. Financial support was provided by Millennium Nucleus P10-022-F (Chilean Ministry of Economy) and additionally by grant FONDECYT 1100221 and grant 284405 from the European Union FP7 programme.
The authors declare no competing financial interests.
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Casassus, S., van der Plas, G., M, S. et al. Flows of gas through a protoplanetary gap. Nature 493, 191–194 (2013). https://doi.org/10.1038/nature11769
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