Abstract
Direct images of protoplanets embedded in disks around infant stars provide the key to understanding the formation of gas giant planets such as Jupiter. Using the Subaru Telescope and the Hubble Space Telescope, we find evidence for a Jovian protoplanet around AB Aurigae orbiting at a wide projected separation (~93 au), probably responsible for multiple planet-induced features in the disk. Its emission is reproducible as reprocessed radiation from an embedded protoplanet. We also identify two structures located at 430–580 au that are candidate sites of planet formation. These data reveal planet formation in the embedded phase and a protoplanet discovery at wide, >50 au separations characteristic of most imaged exoplanets. With at least one clump-like protoplanet and multiple spiral arms, the AB Aur system may also provide the evidence for a long-considered alternative to the canonical model for Jupiter’s formation, namely disk (gravitational) instability.
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Data availability
With the exception of data from the first CHARIS epoch (obtained during engineering observations), all raw SCExAO data are available for public download from the Subaru SMOKA archive: https://smoka.nao.ac.jp/. The first epoch data are available upon request. Keck data are available from the Keck Observatory Archive (https://koa.ipac.caltech.edu/cgi-bin/KOA/nph-KOAlogin); HST data are available from the Milkulski Archive for Space Telescopes (https://archive.stsci.edu/missions-and-data/hst). Processed data are made available from the corresponding author upon reasonable request.
Code availability
Data reduction pipelines used to create CHARIS data cubes and perform subsequent processing are publicly available on GitHub (https://github.com/PrincetonUniversity/charis-dep and https://github.com/thaynecurrie/charis-dpp).
References
Borucki, W. et al. Kepler planet-detection mission: introduction and first results. Science 327, 977–980 (2010).
Pollack, J. B. et al. Formation of the giant planets by concurrent accretion of solids and gas. Icarus 124, 62–85 (1996).
Marois, C. et al. Direct imaging of multiple planets orbiting the star HR 8799. Science 322, 1348–1352 (2008).
Carson, J. Direct imaging discovery of a ‘super-Jupiter’ around the late B-type star κ And. Astrophys. J. Lett. 763, L32 (2013).
Currie, T. et al. Direct imaging and spectroscopy of a candidate companion below/near the deuterium-burning limit in the young binary star system, ROXs 42B. Astrophys. J. Lett. 780, L30 (2014).
Chauvin, G. et al. Discovery of a warm, dusty giant planet around HIP 65426. Astron. Astrophys. 605, L9 (2017).
Boss, A. P. Evolution of the solar nebula. IV. Giant gaseous protoplanet formation. Astrophys. J. 503, 923–937 (1998).
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).
Haffert, S. Y. et al. Two accreting protoplanets around the young star PDS 70. Nat. Astron. 3, 749–754 (2019).
Muto, T. et al. Discovery of small-scale spiral structures in the disk of SAO 206462 (HD 135344B): implications for the physical state of the disk from spiral density wave theory. Astrophys. J. Lett. 748, L22 (2012).
Jovanovic, N. et al. The Subaru Coronagraphic Extreme Adaptive Optics System: enabling high-contrast imaging on solar-system scales. Publ. Astron. Soc. Pac. 127, 890 (2015).
Groff, T. D. et al. Laboratory testing and performance verification of the CHARIS integral field spectrograph. Proc. SPIE 9908, 99080O (2016).
van der Marel, N. et al. On the diversity of asymmetries in gapped protoplanetary disks. Astron. J. 161, 33 (2021).
Tang, Y.-W. et al. Planet formation in AB Aurigae: imaging of the inner gaseous spirals observed inside the dust cavity. Astrophys. J. 840, 32 (2017).
Vorobyov, E., Zakhozhay, O. & Dunham, M. Fragmenting protostellar discs: properties and observational signatures. Mon. Not. R. Astron. Soc. 433, 3256–3273 (2013).
Blunt, S. et al. orbitize!: a comprehensive orbit-fitting software package for the high-contrast imaging community. Astron. J. 159, 89 (2020).
Hashimoto, J. et al. Direct imaging of fine structures in giant planet-forming regions of the protoplanetary disk around AB Aurigae. Astrophys. J. Lett. 729, L17 (2011).
Perrin, M. D. et al. The case of AB Aurigae’s disk in polarized light: is there truly a gap? Astrophys. J. Lett. 707, L132–L136 (2009).
Norris, B. et al. The VAMPIRES instrument: imaging the innermost regions of protoplanetary discs with polarimetric interferometry. Mon. Not. R. Astron. Soc. 447, 2894–2906 (2015).
Pecaut, M. J. & Mamajek, E. E. Intrinsic colors, temperatures, and bolometric corrections of pre-main-sequence stars. Astrophys. J. Suppl. Ser. 208, 9 (2013).
Spiegel, D. S. & Burrows, A. Spectral and photometric diagnostics of giant planet formation scenarios. Astrophys. J. 745, 174 (2012).
Baraffe, I., Chabrier, G., Barman, T. S., Allard, F. & Hauschildt, P. Evolutionary models for cool brown dwarfs and extrasolar giant planets. The case of HD 209458. Astron. Astrophys. 402, 701–712 (2003).
Brandt, T. D. The Hipparcos–Gaia Catalog of Accelerations: Gaia EDR3 edition. Astrophys. J. Suppl. Ser. 254, 42 (2021).
Zhu, Z. Accreting circumplanetary disks: observational signatures. Astrophys. J. 799, 16 (2015).
Wagner, K., Apai, D. & Kratter, K. M. On the mass function, multiplicity, and origins of wide-orbit giant planets. Astrophys. J. 877, 46 (2019).
Forgan, D. & Rice, K. Towards a population synthesis model of objects formed by self-gravitating disc fragmentation and tidal downsizing. Mon. Not. R. Astron. Soc. 432, 3168–3185 (2013).
Boccaletti, A. et al. Possible evidence of ongoing planet formation in AB Aurigae. A showcase of the SPHERE/ALMA synergy. Astron. Astrophys. 637, L5 (2020).
Gaia Collaboration Gaia Early Data Release 3. Summary of the contents and survey properties. Astron. Astrophys. 649, A1 (2021).
Gaia Collaboration Gaia Data Release 2. Summary of the contents and survey properties. Astron. Astrophys. 616, A1 (2018).
deWarf, L. E., Sepinsky, J. F., Guinan, E. F., Ribas, I. & Nadalin, I. Intrinsic properties of the young stellar object SU Aurigae. Astrophys. J. 590, 357–367 (2003).
Kenyon, S. J., Gomez, M. & Whitney, B. A. in Handbook of Star Forming Regions: Volume I, The Northern Sky (ed. Reipurth, B) 405–458 (Astronomical Society of the Pacific, 2008)
Grady, C. et al. Hubble Space Telescope Space Telescope Imaging Spectrograph coronagraphic imaging of the Herbig AE star AB Aurigae. Astrophys. J. Lett. 523, L151–L154 (1999).
Oppenheimer, B. R. et al. The Solar System-scale disk around AB Aurigae. Astrophys. J. 679, 1574–1581 (2008).
Fukagawa, M. et al. Spiral structure in the circumstellar disk around AB Aurigae. Astrophys. J. Lett. 605, L53–L56 (2004).
Dong, R. The missing cavities in the SEEDS polarized scattered light images of transitional protoplanetary disks: a generic disk model. Astrophys. J. 750, 161 (2012).
Zhu, Z., Nelson, R. P., Dong, R., Espaillat, C. & Hartmann, L. Dust filtration by planet-induced gap edges: implications for transitional disks. Astrophys. J. 755, 6 (2012).
Lawson, K. et al. High-contrast integral field polarimetry of planet-forming disks with SCExAO/CHARIS. Proc. SPIE 11823, 118230D (2021).
Marois, C., Lafrenière, D., Doyon, R., Macintosh, B. & Nadeau, D. Angular differential imaging: a powerful high-contrast imaging technique. Astrophys. J. 641, 556–564 (2006).
Debes, J. H., Ren, B. & Schneider, G. Pushing the limits of the coronagraph occulters on Hubble Space Telescope/Space Telescope Imaging Spectrograph. J. Astron. Telesc. Instrum. Syst. 5, 035003 (2019).
Brandt, T. D. et al. Data reduction pipeline for the CHARIS integral-field spectrograph I: detector readout calibration and data cube extraction. J. Astron. Telesc. Instrum. Syst. 3, 048002 (2017).
Currie, T. et al. No clear, direct evidence for multiple protoplanets orbiting LkCa 15: LkCa 15 bcd are likely inner disk signals. Astrophys. J. Lett. 877, L3 (2019).
Tannirkulam, A. A tale of two Herbig Ae stars, MWC 275 and AB Aurigae: comprehensive models for spectral energy distribution and interferometry. Astrophys. J. 689, 513–531 (2008).
Currie, T. et al. A combined Subaru/VLT/MMT study of planets orbiting HR 8799: implications for atmospheric properties, masses, and formation. Astrophys. J. 729, 128 (2011).
Soummer, R., Pueyo, L. & Larkin, J. Detection and characterization of exoplanets and disks using projections on Karhunen–Loève eigenimages. Astrophys. J. Lett. 755, L28 (2012).
Currie, T. et al. Direct imaging confirmation and characterization of a dust-enshrouded candidate exoplanet orbiting Fomalhaut. Astrophys. J. Lett. 760, L32 (2012).
Currie, T. et al. Resolving the HD 100546 protoplanetary system with the Gemini Planet Imager: evidence for multiple forming, accreting planets. Astrophys. J. Lett. 814, L27 (2015).
Stolker, T. et al. Scattered light mapping of protoplanetary disks. Astron. Astrophys. 596, A70 (2016).
Hines, D. C., Schmidt, G. D. & Schneider, G. Analysis of polarized light with NICMOS. Publ. Astron. Soc. Pac. 112, 983–995 (2000).
Mawet, D. et al. Fundamental limitations of high contrast imaging set by small sample statistics. Astrophys. J. 792, 97 (2014).
Krist, J. in Astronomical Data Analysis Software and Systems IV (eds Shaw, R. A. et al.) 349–352 (Astronomical Society of the Pacific, 1995)
Pinilla, P. et al. Trapping dust particles in the outer regions of protoplanetary disks. Astron. Astrophys. 538, A114 (2012).
Min, M., Dullemond, C. P., Dominik, C., de Koter, A. & Hovenier, J. W. Radiative transfer in very optically thick circumstellar disks. Astron. Astrophys. 497, 155–166 (2009).
Brandenburg, A. & Dobler, W. Hydromagnetic turbulence in computer simulations. Comput. Phys. Commun. 147, 471–475 (2002).
Dullemond, C., Juhasz, A. & Pohl, A. RADMC-3D: a multi-purpose radiative transfer tool. Astrophysics Source Code Library ascl:1202.015 (2012).
Acknowledgements
We thank A. Boccaletti for many helpful conversations regarding the AB Aur protoplanetary disk and system properties. Z. Zhu generously provided circumplanetary disk models; S. Blunt provided expert advice on MCMC-based orbit fitting. We thank the Subaru, NASA-Keck and Hubble Space Telescope Time Allocation committees for their generous allotment of observing time. This research is based in part on data collected at Subaru Telescope, which is operated by the National Astronomical Observatory of Japan. We acknowledge the very significant cultural role and reverence that the summit of Maunakea holds within the Hawaiian community. We are most fortunate to have the opportunity to conduct observations from this mountain. This paper makes use of the following ALMA data: 2012.1.00303.S. ALMA is a partnership of ESO (representing its member states), NSF (USA) 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 work was partially funded under NASA/XRP programmes 80NSSC20K0252 and NNX17AF88G. The development of SCExAO was supported by the Japan Society for the Promotion of Science (Grant-in-Aid for Research nos. 23340051, 26220704, 23103002, 19H00703 and 19H00695 and partly 18H05442, 15H02063, and 22000005), the Astrobiology Center of the National Institutes of Natural Sciences, Japan, the Mt Cuba Foundation and the director’s contingency fund at Subaru Telescope.
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T.C. conceived of the project, (co-)led the total intensity data reduction, performed the spectroscopic and orbital analysis, and wrote the manuscript. K.L. and J.W. led the polarized intensity data reduction and the polarimetry-constrained PSF subtraction method for CHARIS. G.S. planned the STIS observations and co-led the HST/STIS and NICMOS reductions. W.L. generated the hydrodynamical models used to compare the real data with models of planet formation. C.G. aided with project and observing planning. O.G., J.L., S.V., V.D., N.J., F.M. and N.S. oversaw the operation of SCExAO. M.T. provided project management. T.K and H.K. planned and obtained one epoch of CHARIS data. T.B. provided dynamical mass estimates. T.U. and B.N. contributed VAMPIRES data reduction steps. R.D. and T.M. aided with interpreting planet-induced disk features. J.C., T.T. and T.G. lead the operation and maintenance of CHARIS. K.W.-D. and W.J. planned the STIS observations. N.v.d.M. provided the AB Aur ALMA image. M.S. obtained SpeX data. The authors all contributed to the original observing proposals, data acquisition and/or paper draft comments.
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Currie, T., Lawson, K., Schneider, G. et al. Images of embedded Jovian planet formation at a wide separation around AB Aurigae. Nat Astron 6, 751–759 (2022). https://doi.org/10.1038/s41550-022-01634-x
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DOI: https://doi.org/10.1038/s41550-022-01634-x
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