Targets of opportunity

Starting in semester 2026A, the ING offers Target of Opportunity (ToO) observations as part of the WEAVE Open Time Programme, using the LIFU mode only. ToO proposals address astronomical events that require immediate observation and whose timing does not align with the standard trimestral proposal preparation and OB submission cycle. Due to their disruptive nature, ToO observations will be capped at a maximum of 30% of the available Open Time for each national TAC every semester.

Applications for ToOs should be submitted to the TACs in the same way as regular proposals for scheduled time. ToO proposals will be evaluated in the same way as regular Open Time proposals but will only be scheduled if they are ranked in the highest category Band A.

Triggering teams of allocated programmes can submit their ToO requests following instructions at Triggering WEAVE Targets of Opportunity.

At present, ING supports next day triggers: for an event scheduled to be observed on a given night, the trigger must be received by the Observatory no later than 12:00 noon on the preceding day. ING will strive to execute ToO programmes on a shorter timescale on a best-effort basis. ING anticipates executing at most one ToO trigger per night, on a first-come, first-served basis.

The reduced observations will be available on the WEAVE Operational Repository on a few days after observations.

If observations of an unpredictable rare or transient event are required at short notice, and they can be justified by the unique scientific opportunity these observations represent, please apply for a WEAVE ING Director's Discretionary Time (DDT) proposal.