恒星物理研究组知识库

The very active RS CVn-type star UX Ari was observed using high-resolution echelle spectrograph attached to the 2.16m telescope of Xinglong station in Nov.-Dec. 2001 and Dec. 2002. By means of synthetic spectral subtraction method, the information about chromospheric activity of the system was obtained through several chrornospheric activity indicators Hel D(3), NaI D(1)D(2), H alpha, and Call IRT lines. Based on the analysis for these activity indicators, we found that the chromospheric activity of UX Ari showed obvious orbital modulation phenomenon, and the favorite active longitudes were around the quadratures of the binary system. During the two observing runs, hot plage and very strong optical flare events were detected, which were always happened around the favorite active longitudes of the system. Moreover, they were linked with the photospheric starspots in spatial structure, and appeared just above the main starspots.