AB Aurigae


AB Aurigae is a Herbig Ae star in the Auriga constellation. It is known for hosting a dust disk that may harbour a condensing planet or brown dwarf. The star could host a possible substellar companion in wide orbit. The star is part of the young Taurus-Auriga association, which is located in the Taurus Molecular Cloud.

Protoplanetary disk

In 2017 scientists used the Atacama Large Millimeter/submillimeter Array to take an image of the protoplanetary disk around AB Aurigae. The image showed a dusty disk which has a radius of about 120 astronomical units and a distinct "gap". Inside this gap gaseous spiral arms are detected in CO.

Planetary system

Oppenheimer et al. observed an annulus feature in AB Aurigae's dust disk between 43 and 302 AU from the star, a region never seen before. An azimuthal gap in an annulus of dust at a radius of 102 AU would suggest the formation of at least one small body at an orbital distance of nearly 100 AU. Such object could turn out either a massive planetary companion or more likely a brown dwarf companion, in both cases located at nearly 100 AU from the bright star. So far the object is unconfirmed.
Observations with ALMA found two gaseous spiral arms inside the disk. These are best explained by an unseen planet with a semimajor axis of about 60-80 au. An additional planet with a semimajor axis of 30 au and with a large pitch angle compared to the disk could explain the emptiness of the inner dusty disk.

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