| Abstract |
Dust forming events around asymptotic giant branch stars are important for understanding dust formation process and dust supply in the galaxy. There is some evidence of its 100-yr scale variability, but it is not fully understood. For finding them, the long period variables expected to have such variability are searched based on the difference of mid-infrared color in the all-sky data of IRAS and AKARI, separated by about 20 years. 12 objects of them are observed with the MAX38/miniTAO (Wavelength: 9-12 microns). Some of the targets show weak spectral change from IRAS/LRS spectra. The long-term variability will be discussed based on these results. |
