Weak-line T Tauri stars are pre-main sequence stars that have H&alpha lines in emission, but at strengths less than 10 Å (Bastian et al. 1983). (For a recent review, see section 1A in Walter et al. 2000) The c2d Legacy Team will make sensitive observations of the IR emission from wTTs to see if they have disks in transitional stages of evolution. NOAO optical spectroscopy has also been obtained to help interpret the results. A review of program elements and facts about wTTs and disks is linked as follows:

• Why use SIRTF to study wTTs
• What stars will c2d observe?
• What will we learn from optical spectroscopy of the sample?
• What products will be available to the community?
• How are disk properties determined from SIRTF observations?
• How can I learn more about disks and weakline T Tauri stars?
• Where can I see image studies of circumstellar disks?

These observations will settle an important question in planet formation studies:

Do wTTs have evolved disks or NO disks?

Since wTTS make up a large fraction of young stars, the answer to this question has very important consequences for the iverall prevalence of planetary systems. A related SIRTF Legacy team, FEPS, will make complementary studies of disks in more evolved stars.