Photometric Behavior of the Herbig Ae Star VX Cas in the Near-Infrared and Optical Ranges of the Spectrum

This paper presents the results of the study of long-term photometric activity in the near infrared spectral region of the young Herbig Ae star VX Cas belonging to the family of irregular UX Ori variables. The infrared data were obtained in 2003–2017 at the Campo Imperatore Observatory (Italy) using the Pulkovo telescope AZT-24 in Johnson’s photometric bands JHK . Additional optical photometry from various sources was used as well. It was shown that the observed photometric activity of the star in the J band and partly in the H band was caused mainly by variations in circumstellar extinction in the protoplanetary disk. In a number of episodes, anticorrelation was observed between brightness variations in the optical V band and H and K bands: the brightness in the H and K bands increased with weakening of the brightness in the V band. This indicates that the gas and dust clouds that screened the star from the observer consisted of hot dust and were located near the sublimation zone.