T Tauri

T Tauri is a system of three stars that is the progenitor of the term T-Tauri star used for similar young variable stars. T Tauri was discovered in 1852, discovered to be a binary in 1981, and a triple in 1997, the three now known as T Tau N (for "north"), T Tau Sa and T Tau Sb. The classification-term T-Tauri star was coined in 1945 when what was observed was T Tau N, which can be observed in visible light, while the other two are largely infrared. T Tauri illuminates a nearby nebula, NGC 1555. Characteristics (T Tau N):

• Taurus - constellation.
• 04h21m59.43445s - right ascension.
• +19deg32m06.4182s - declination.
• +10.27 (+9.3 to +14) - apparent magnitude.
• 144 pc - distance.
• G5V:e - spectral type.
• 2.1 - mass(solar).
• +1.22 - B-V color index.

T Tauri has proven to have unusual characteristics, giving it continuing research interest, but make it somewhat less of a representative of what are now labeled T Tauri stars.