Why are T Tauri stars common in young star-forming regions?
Most of the brightest stars are older yellow stars, but a few young blue stars are also visible. This picture is a composite of three images taken by the Hubble Space Telescope.
T Tauri stars are common in young star-forming regions because they represent a specific, early stage of stellar evolution for low-mass stars. These stars are newly formed from the gravitational condensation of interstellar gas and dust and are still in the process of contracting toward the main sequence.123
Because they are very youngâtypically less than 10 million years oldâthey are found in the same locations where they were recently born, known as T associations. These associations consist of loose aggregates of stars that have not yet had sufficient time to disperse from their common site of formation.23
During this phase, T Tauri stars are relatively unstable and have not yet reached the internal temperatures required to sustain hydrogen fusion. They remain in this state for tens of millions of years, deriving their energy from gravitational contraction until they eventually settle onto the main sequence.12