T Tauri star
The secondary component of the system is Chi Tauri B, separated about 19″ from Chi Tauri A. It was thought to be a post-T Tauri star from its unusual spectrum, but later studies ruled this out. It is a double-lined spectroscopic binary—the two stars are not resolved but their spectra have periodic Doppler shifts indicating orbital motion. The two stars are an F-type star and a G-type star, respectively, and are designated Ba and Bb.