A planned IT Maintenance will take place at ESO between Saturday, 11 April 2026 at 08:00 CEST and Sunday, 12 April 2026 at 24:00 CEST. From 08:00 CEST on Saturday all ESO services including p1, p2, the Operations Helpdesk and the Scientific Archive could be subject to intermittent outages. We apologize for any inconvenience.

Service Mode Policies

The ESO Optical/Infrared Telescopes Science Operations Policies document, approved at the 154^th Council meeting in June 2020, describes the policies applied to the selection of observations, the operations and the data handling of all ESO optical/near-infrared telescopes.

The following pages list science operations policies implementation specific to service mode that have to be considered for the preparation of Phase 2 material and the execution of observations in service mode:

Phase 2 constraints must agree with Phase 1 request.
Phase 2 targets must agree with the ones submitted at Phase 1.
The total execution time must not exceed the time allocated to the observing run.
Policy regarding the OB run-time failure.
Policy regarding the execution of time-critical OBs.

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This page is valid for all instruments

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Service Mode Policies

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