A visual bandlight curve for V1057 Cygni. The main plot shows the long-term variability, and the inset shows the short-term variability. Adapted from Kopatskaya et al. (2002)[1] and Clarke et al. (2005).[2]
The initial classification of the primary was as a young T Tauri star.[4] During 1969–1970 it underwent a nova-like outburst, increasing in brightness by five magnitudes and emitting a strong mass outflow. For the next ten years the brightness stayed at a plateau before decreasing rapidly in the mid–1990s, accompanied by a change in its spectrum. As of 2013, it is 1.5 magnitudes brighter than it was before the nova-like event.[8] The mass of FU Ori objects is estimated to be in the range of 0.3–0.7 M☉.[4]
A faint binary companion was discovered in 2016, and designated component B. It is located at a projected separation of 30±5 AU from the primary, with a possible orbital period of ~300 years. The 1970 outburst of the primary may have been caused by torque of its accretion disk by the companion.[4]