New Look at the Structure of the Nearest Circumstellar Environment of the Weak-Line T Tauri Star V718 Per

Abstract

In this paper, we have analyzed the properties of the photometric and spectral variability of young star V718 Per, a member of the cluster IC 348, in terms of its possible binarity. The most realistic is the model where the main component of the V718 Per A system—with an effective temperature of 5200 K—is periodically shielded by two extended dust structures consisting of large particles and moving around the star in resonance with two planets. Their orbital periods are 4.7 years and 213 days. Their ratio with high accuracy is equal to 1 : 8, and the ratio of the large semi-axes is 1 : 4. The masses of the planets have not exceeded \(6 \,{{M}_{{{\text{Jup}}}}}\). At the moments of total eclipses V718 Per A, the radiation of the system has been dominated by a colder component with an effective temperature of \(4150 \pm 100\) K, which has explained the reddening of the star observed in the brightness minima, as well as its spectral changes during brightness weakening. Speckle interferometric observations performed using the 2.5-m telescope of the Sternberg Astronomical Institute have made it possible to estimate the upper limit of the angular distance between the components of the system: ≤0.1\('' \), which is equivalent to a projection distance of ≤30 AU. The unique feature of this system has been that the planes of the planetary orbits practically coincide with the line of sight. Such an orientation of the system has been most favorable for measuring fluctuations in the radial velocity of a star caused by the orbital motion of planets, as well as for observing planetary transits along the disk of the main component of the system.