The Doppler imaging of active star Sigma Gem in 2011

Gu Sheng-hong, shenghonggu@ynao.ac.cn, Yunnan Observatory, China
Telting John, Nordic Optical Telescope
Collier Cameron Andrew, St. Andrews University

Abstract
The active star Sigma Gem was observed by using high-resolution spectrograph FIES of Nordic Optical Telescope from Mar. to May, 2011. A dataset with good quality was obtained and reduced by using IRAF package. The result 1D spectra are used to derive the composite profile series by means of least-squares deconvolution, which is reversed to get Doppler imaging of its spot pattern. Finally, the new map is compared with the previous results, and the evolution of spot patterns is discussed.