The GAS (Grupo de Astronomos de Soporte del IAC) reminds that, other than the biannual call for proposal managed by the CAT (Comisión de Asignación de Tiempo nocturno en los Telescopios de Canarias), other ways exist to request observing time to the GTC, WHT, INT, NOT, LT and, occasionally, to the TNG. These are the IAC Director Discretionary Time (DDT) and the Service Time. DDT and Service Time proposal can be submitted at any time, in agreement with the rules reported in the Observatorios de Canarias (OOCC) website.

The scientific evaluation of the proposals is done by the CAT (service) and by the IAC Director advised by international experts (DDT). The feasibility of the observing programs is verified by the staff of the different telescopes.

Note that different procedures apply to different telescopes:

GTC – DDT proposals for the GTC can be submitted at any time. Approved proposals can be executed in both visitor or queue mode, according to the PI choice.

WHT, INT, NOT and TNG – DDT and Service nights managed by CAT are assigned every semester. Interested investigators have to send their proposal asking for specific nights. Proposal have ideally to be submitted 20 and 10 days before the observing night for DDT and service time, respectively. DDT observations will be always collected in visitor mode. Service programmes will be executed by the IAC support astronomers (INT, NOT, TNG) or by the ING staff (WHT). More informations are provided in DDT at WHT, NOT, INT and TNGand Spanish Service Time.

LT – Service observations (“LT reactive time”) have been recently implemented within the CAT operations (semesters 2016A and 2016B). Proposals can be submitted at any time during the corresponding semester. Observations will be exetued in queue mode.