The X-ray spectra of late type stars can generally be well fitted by a two temperature component model of the corona. We find that the temperatures of both components are strong functions of stellar age, although the temperature of the hotter plasma in the corona shows a larger scatter and is probably affected by the activity of stars, such as flares. We confirm the power-law decay of the temperature of the hot plasma, but the temperature of the cool plasma component decays linearly with log(age).

• HWANKYUNG SUNG(Department of Astronomy and Space Science, Sejong University) Corresponding Author
• M. S. BESSELL(Research School of Astronomy and Astrophysics, Australian National University)
• HUGUES SANA(European Southern Observatory)