The Herbig Be Star IL Cep A as a Long-Periodic Spectroscopic Binary

Autor: M. A. Pogodin, G. R. Bahaddinova, U. Z. Bashirova, N. Z. Ismailov
Rok vydání: 2020
Předmět:
Zdroj: Astronomy Reports. 64:23-33
ISSN: 1562-6881
1063-7729
DOI: 10.1134/s1063772920010047
Popis: The results of long-term spectral monitoring of the Herbig Be star IL Cep A are presented. A smooth variation in the parameters of the Нα and Нβ line emission component has been discovered. The helium absorption lines He I λ4922 and 5876 A show seasonal changes, however, these changes do not correlate with changes in hydrogen emission. The radial velocities of the narrow lines D Na I and DIB λ5780, 5796 A correspond to that of the interstellar medium. The hydrogen emission lines are apparently formed in a triple system, including a close pair of B stars and a remote low-mass K–A component. The orbital elements of this system were calculated using an approximate spectral binary model, where a close pair of massive B stars was considered as one massive component. The rationale for this approach for determining the elements of the orbit is given. The orbital period P = 3550 ± 28 days is determined and some other parameters of the orbit are estimated.
Databáze: OpenAIRE