Abstract
Taiwan Earthshine and AsteroSeismology Telescopes(EAST) is a global network used to study earthshine and asteroseismology. The ultimate goal of EAST is to construct fully automatic observatories around the globe and obtain data uninterruptly. At present, two stations are constructed. The prototype system is at the campus of National Tsing Hua University, Hsinchu, Taiwan. Besides, the first system has been installed at Teide Observatory, Tenerife, Spain. EAST stations can be operated automatically or controlled remotely through the Internet. In this thesis, preliminary result on asteroseismology with Taiwan EAST Network is presented. We observed two delta scuti variable stars, GN And and BI CMi, with EAST at Hsinchu and Tenerife. Light curves of GN And, a 5-magnitude star, show a regular oscillating period of 0.07 days, amplitude of 0.05 magnitudes, and the estimated error is less than 2%. Light curve of BI CMi, a 9-magnitude star, has a regular oscillating period of 0.11 days, amplitude of 0.07 magnitude, and the estimated error is down to 1%. This result indicates EAST can measure 9-magnitude variable stars down to 1% variations. Two photometry methods, aperture photometry and PSF photometry, are used to analyze data. We assume a symmetric Gaussian distribution on a star profile for PSF photometry. Light curves obtained from both methods have little difference, which means that, for a disperse star distribution, the difference is not obvious. The error of measured magnitude is estimated based on the spatial fluctuation of the clean images. We assume the spatial fluctuation relative to the smooth point spread function(PSF) of the target star is due to errors. The error estimated by this assumption is quite small. There are several interesting scientific topics that can be studied with EAST data, such as searching for new variable stars and occultation events.