Images of Embedded Jovian Planet Formation At A Wide Separation Around AB Aurigae

TL;DR

This paper reports the direct imaging discovery of a jovian protoplanet around AB Aurigae at a wide separation, providing insights into early planet formation processes and potential gravitational instability mechanisms.

Contribution

It presents the first direct imaging evidence of a protoplanet at wide separation around AB Aurigae, supporting theories of embedded planet formation and disk instability.

Findings

Detection of a jovian protoplanet at 93 au around AB Aurigae

Identification of additional candidate planet formation sites at 430-580 au

Evidence supporting disk gravitational instability as a planet formation mechanism

Abstract

Direct images of protoplanets embedded in disks around infant stars provide the key to understanding the formation of gas giant planets like Jupiter. Using the Subaru Telescope and Hubble Space Telescope, we find evidence for a jovian protoplanet around AB Aurigae orbiting at a wide projected separation (93 au), likely 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: disk (gravitational) instability.