おうし座T型星
The initial classification of the primary was as a young T Tauri star. 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. The mass of FU Ori objects is estimated to be in the range of 0.3–.