Keywords:Protoplanetary disk, WW Cha
Recent observations by ALMA have revealed substructures such as gap and ring in protoplanetary disk. These substructures could be clues how planets form within the disk. We present the ALMA observation of the disk around WW Chameleon in Band 6 in Cycle 6. WW Chameleon is a young sstar (age is about 0.2 Myr) with about solar mass, and its distance is about 192 pc, and it is known to be a high accretor with a massive disk. WW Chameleon is also reported to be probable spectroscopic binary. The modeling of SED in the previous study suggested the large cavity with the radius of about 50 AU. If the large cavity opens, our observation with the beam size of ~10 AU could resolve it. However, an image given by our observation does not show such a large cavity. Moreover, although the large-scale spiral arms were detected in the image of NIR observation given by SPHERE, the structure looks axisymmetric in the ALMA image. We modeled the structure of the disk by fitting the visibility and found that the inner cavity can be very small (~a few AU). This visibility fitting also suggest several rings and steep cliff of the dust thermal emission. Assuming the temperature distributions, we also estimated the distribution of the dust density. In this poster, we present the results of our analysis and discuss the origin of these structures.