A Deep Spectral Observation of T Tauri

The T Tau system is believed to be in a critical transition regime from embeddedprotostars to optically revealed T Tau stars. As part of a detailedinvestigation of this system, we propose to obtain the first Xray gratingspectra and very deep CCD spectra in conjunction with timeresolved UVphotometry. T Tau provides a unique opportunity to record a grating spectrum ofsuch a transition object. Our principal scientific objectives are (i) a searchfor fluorescent lines; (ii) line diagnostics with the RGS; (iii) flare physics,and (iv) ultraviolet variability, possibly induced by accretion flows or,alternatively, by highenergy particles. truncated!, Please see actual data for full text [truncated!, Please see actual data for full text]