Title: Photometric and spectral studies of pre-main-sequence stars
Author(s): E. Semkov (Oral)

ABSTRACT
In the pre-main-sequence stage of evolution the young stellar objects show different types of photometric variability. We report results from photometric and spectral observations in the regions of star formations: NGC 7129, NGC 7000 and Alpha Persei. Our investigations have for an object a long-term photometry of known pre-main sequence objects and discovery of new variable stars. The wide-field spectral studies ware used to reveal the new candidates for pre-main sequence objects. Using precise CCD photometric observations we try to determine their distribution on the spectrum-luminosity diagram.