T Tauri

T Tauri belongs in a particular class of variable stars and is itself totally unpredictable. In a period as short as a few weeks, it might change magnitude rapidly and other times remain constant for months on end. It is a typical star in temperature and mass - and its spectral signature is very similar to Sol's chromosphere - but the resemblance ends there. T Tauri is a star in the initial stages of birth!

All the stars in T Tauri's category are pre-main sequence and are considered "proto-stars". In other words, they continuously contract and expand, shedding some of their mantle of gas and dust. This gas and dust is caught by the star's rotation and spun into an accretion disc - which might be more properly referred to as a proto-planetary disc. By the time the jets have finished spewing and the material is pulled back to the star by gravity, the proto-star will have cooled enough to have reached main sequence and the pressure may have allowed planetoids to form from the accreted material.

The star is accompanied by the nebula NGC 1555.