Poster abstract details

We study the varibility and period-luminosity relation for red supergiant stars from published papers by using the latest optical and infrared survey data. The typical time span of optical data is larger than 3000 days from the All Sky Automated Survey and the MAssive Compact Halo Objects project. Infrared data are come from the Two Micron All Sky Survey and \textit{Spitzer}/SAGE Legacy Program. We use the color-magnitude diagram and two-color diagram to identify all the candidates and determine periods by using the phase dispersion minimization method, Fourier analysis and Wavelet analysis. About half of our available targets are in irregular phase of variability which indicate the dominated effect by the convection in this evolutionary phase. About one fifth of available targets are semi-regulars and the reset is long secondary variable stars. We derived a slightly loose relation from the semi-regulars in K-band and more strict tendency is obvious in longer wavelengths which suggest that the large number of RSGs is needed for deriving the relation and the best wavelength apply for it is larger than 3 $\mu$m and less than 5 $\mu$m. The long secondary variable stars do not have any linear relations by themselves or combine with semi-regulars.