Investigations of the Periodic Variables in the Catalina and Linear Databases

In this study we continue spectral class determinations for large numbers of optically faint periodic variables taken from the Catalina Surveys Data Release 1 (CSDR1) and LINEAR data sets. Spectral classes and physical parameters are presented for 1184 periodic variables with periods P ≥ 10 days, taken from modern large sky area spectroscopic and photometric databases, including LAMOST (Large Sky Area Multi-Object Fiber Spectroscopic Telescope), SDSS (Sloan Digital Sky Survey), the Hamburg Quasar Survey (HQS), the Hamburg/ESO Survey (HES), and Gaia Data Release 2 (DR2). In Gaia DR2 catalogue, luminosities are presented for 276 objects and radial velocities (RV) for 108 objects out of 1184. Spectral classes were confirmed for more than 650 objects. The majority of the variables are found to be F, G, K, M dwarfs and giants, a few dozen carbon (C) stars (N-type Asymptotic Giant Branch (AGB) stars), and a few S stars. Some periodic variables are blue objects, such as B and A stars. The periods are in the range 10 ≤ P ≤ 1504 days and Catalina magnitudes in range 11.5 ≤ V ≤ 20.0 mag. Finding new and faint evolved AGB stars in the halo of our Galaxy is the first priority. A catalogue containing multiparameter data for 1184 periodic variables from modern astronomical databases has been generated.