We present an atlas of a group of bright stars in the range of spectral classes F-G and luminosity classes Ⅰ-Ⅴ.The spectra were obtained with spectral resolut
Quantities characterizing temporal property, e.g., power density, co-herence, and time lag, can be defined and calculated directly in the time domain without us
We present the results of a time-series CCD photometric survey ofvariable stars in the field of the open cluster NGC 7789. In a field of about onedegree centeri