Submission of TOO triggers and DDT requests with response windows <= 5 days will trigger pagers/phones for selected CXC personnel - some 24 hrs per day 7 days per week and some between 8-22H (EDT/EST) 7 days per week. Please be sure that your program requires rapid turn-around before submitting requests with response windows starting at 5 days or less, and to the extent possible please submit such requests during normal EDT/EST weekday working hours.

TOOs/DDT requests with Medium turn-around times having response windows from 5 to 30 days trigger pagers/phones on weekend days as well as on work days from 8-22H EDT/EST. To the extent possible please submit such triggers/requests during normal EDT/EST weekday working hours.

Peer-reviewed TOOs are TOO proposals that were submitted and accepted as a result of the Chandra Call for Proposals (CfP). Since their scientific objectives have already been approved, we require only confirmation of a few details and a brief description of how the trigger criteria has been met. Please use the form below to identify the TOO you wish to trigger.

Unanticipated TOOs are charged to Director's Discretionary Time. These will not have not been previously accepted through the Chandra Call for Proposals. For the unanticipated TOOs, a compelling scientific case must be made for inserting them into the mission timeline. To submit an RfO (Request for Observation) of this type, please see the instructions for Director's Discretionary Time.