An 80 au cavity in the disk around HD 34282
Pinte, C.; Ménard, F.; van der Plas, G.; Avenhaus, H.; Casassus, S.; Canovas, H.; Caceres, C.; Cieza, L.
France, Chile, Spain, Switzerland
Abstract
Context. Large cavities in disks are important testing grounds for the mechanisms proposed to drive disk evolution and dispersion, such as dynamical clearing by planets and photoevaporation.
Aims: We aim to resolve the large cavity in the disk around HD 34282, whose presence has been predicted by previous studies modeling the spectral energy distribution of the disk.
Methods: Using ALMA band 7 observations we studied HD 34282 with a spatial resolution of 0.10″ × 0.17'' at 345 GHz.
Results: We resolve the disk around HD 34282 into a ring between 0.24'' and 1.15'' (78+7-11 and 374+33-54 au adopting a distance of 325+29-47 pc). The emission in this ring shows azimuthal asymmetry centered at a radial distance of 0.46'' and a position angle of 135° and an azimuthal FWHM of 51°. We detect CO emission both inside the disk cavity and as far out as 2.7 times the radial extent of the dust emission.
Conclusions: Both the large disk cavity and the azimuthal structure in the disk around HD 34282 can be explained by the presence of a 50 Mjup brown dwarf companion at a separation of ≈0.1''.