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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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.
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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.
The authors declare no competing interests.
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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
Nature Astronomy (2022)