Triggers:TTau

T Tauri stars and other young variables and transients

T Cha - example of TTau star from the ASAS data

T Tauri type stars are very young (<math> <10^7 </math> y), low mass (<math> <3 M^{}_\odot </math>) pre-main sequence objects Appenzeller & Mundt 1989.

Characteristics:

• irregular and quasi-periodic variations
• high amplitude (up to 5 mag)
• may have a phase of quiescence (see figure)
• absolute magnitude range: M_V=? to ? mag
• typically do not require a trigger, but watch list of T Tauris would be useful

Below are sample optical spectra of classical T Tauri stars and two FU-ori type eruptive variables.

FRODOspec data from the Liverpool Telescope

FRODOspec data of DG Tau (red), CW Tau (blue) and HL Tau (green)