ALMA image of the dust ring (red) and gaseous spirals (blue) of the circumstellar disk AB Aurigae reveal gaseous spiral arms inside a wide dust gap, providing a hint of planet formation. Credit: ALMA (
ESO/
NAOJ/
NRAO)/Tang et al.
This star 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,[4] which is located in the
Taurus Molecular Cloud.[12] The star itself may recently have encountered a dense cloudlet, which disrupted its debris disk and produced an additional
reflection nebula.[13]
Oppenheimer et al. (2008)[15] 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 an object could turn out to be 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 (likely higher inclination) could explain the emptiness of the inner dusty disk.[3] The outer planet was still not detected as in 2022, putting an upper limit on is mass at 3–4 MJ, inconsistent with the spiral structures observed in the disk.[16] The planet-like clump observed in April 2022 at projected separation 93
AU from star, may be either an accretion disk around newly formed planet or the unstable disk region currently transforming into the
planet.[17] The planet observation was confirmed in July 2022.[18]
^Ducati, J. R. (2002). "VizieR Online Data Catalog: Catalogue of Stellar Photometry in Johnson's 11-color system". CDS/ADC Collection of Electronic Catalogues. 2237.
Bibcode:
2002yCat.2237....0D.
^
abNicolet, B. (1964). "Catalogue of homogeneous data in the UBV photoelectric photometric system". Astronomy and Astrophysics Supplement Series. 34: 1–49.
Bibcode:
1978A&AS...34....1N.