Masses and radii of the components of V1016 Ori

On January 2/3, 2001, eight spectra of the star V 1016 Ori were taken with the 2.6-m Crimean Astrophysical Observatory telescope on the descending bra nch of its eclipse. The spectral range lambda lambda 5299-5365 Angstrom Ang strom was chosen to be without strong lines of the primary B0 star, emissio n lines of the Orion Nebula, and telluric lines. Adding up the spectra and optimum filtering yielded a signal-to-noise (S/N) ratio of similar to 600. We managed to identify thirteen lines of an A star that belong to the secon dary component and seven lines of an M star that presumably belong to theta (1) Ori B1 (third star); the latter lies 0."2 north of the binary system a nd was discovered by speckle interferometry. One of the lines is in emissio n. The radial velocities of both stars were measured. We calculated the com ponents' mass ratio, q = 0.19. We also determined the semiamplitude of the secondary's radial-velocity curve, K-a = 172 km s(-1), the components' mass es, M-a = 21M(circle dot) and M-b = 3.9M(circle dot), and radii, R-a = 3.7R (circle dot) and R-b = 3.6R(circle dot) The measured radial velocity V-r(c) = 33 km s(-1) of theta (1) Ori B1 matches the binary's gamma r velocity, w ithin the error limits, which argues for the assumption that theta (1) Ori B1 is physically associated with the eclipsing system. The superscripts a, b, and c imply that a quantity belongs to the primary star, the secondary s tar, and theta (1) Ori B1, respectively. We estimated an upper limit on the projected rotational velocity for the secondary component and the third st ar, Vsini < 30 km s(-1). (C) 2001 MAIK "Nauka/Interperiodica".