The Near Infrared and Optical Photometric Activity of V517 Cyg

• Published in: Astronomy reports 2023-11, Vol.67 (11), p.1139-1155
• Main Authors: Efimova, N. V., Grinin, V. P., Arkharov, A. A., Potravnov, I. S., Melnikov, S. Yu, Larionov, V. M., Klimanov, S. A., Gorshanov, D. L.
• Format: Article
• Language: English
• Subjects: Amplitudes; Astronomy; D lines; Deposition; Emission lines; H alpha line; Infrared photometry; Light curve; Observations and Techniques; Observatories; Periodic variations; Photometry; Physics; Physics and Astronomy; Stars; Zidovudine
• ISSN: 1063-7729; 1562-6881
• DOI: 10.1134/S1063772923110045

A near infrared and optical photometric study of Herbig star V517 Cyg has been carried out. The infrared data were obtained in 2003–2017 at the Campo Imperatore Observatory (Italy) with the Pulkovo AZT-24 telescope in the Johnson JHK bands. The optical light curves in the Johnson UBVR bands were obtained at the Maidanak observatory. Additional optical photometry from different sources (ASAS, WISE, and AAVSO) was also used. It has been shown that the behavior of V517 Cyg in the near infrared is typical for UX Ori stars. A considerable contribution to the near infrared variability is made by changes in the extinction along the line of sight; however, in the H and K bands, the influence of the disk is strong: there is a significant correlation between V and J magnitudes ( r ∼ 0.84), while H and K magnitudes poorly correlate with V magnitude. The amplitude of variability in the J band is quite large (∼1.8 m ). In the deepest minimum in V band ( ∼ 3.6 m ) the star demonstrates quasi-periodic variations with an amplitude of ∼0.8 m and a period of ∼19 d  (plain).]; and their origin is still unclear. It is possible that these oscillations are caused by the presence of a companion, a cold T Tau star, and related to its rotation period. The spectrum of V517 Cyg reveals typical for UX Ori stars the double-peaked emission line H α . The NaI D lines have the inverse P Cyg profiles, which is indicative of intensive gas accretion onto the star. The accretion rate determined from the equivalent width of the H α line is = 3.6 × 10 –8 per year.