Phase 1 Call for Proposals

Proposals for observations at the ESO telescopes are invited twice a year. A Call for Proposals is issued at the end of February (for observations to be carried out between October 1 of the current year and March 31 of the following year) and at the end of August (for observations to be carried out between April 1 and September 30 of the year following the release of the Call). Proposals must be submitted by the respective deadline (end of March and end of September) using the Web-based p1 interface accessible at Please refer also to the instructions given in the Call for Proposals. The Call for Proposals also gives an overview of the telescopes and instruments that can be applied for, as well as of the applicable policies and procedures.

The proposals are either reviewed by the Observing Programmes Committee (OPC) and the Expert Panels, or assigned to the Distributed Peer Review (DPR) (as of Period 110). The review assignment criteria are published in the Call for Proposals. The OPC and panel members are selected based on scientific excellence and are organised in specialised panels according to their area of scientific expertise. The OPC recommendations and the feedback provided by the DPR serve as basis for final decision on the telescope time allocation by the Director General.

The outcome of the proposal evaluation process is communicated to the applicants by beginning of July (for proposals submitted in March) or by end of December (for proposals submitted in September). Information about successful proposals is published in the telescope time allocation schedule.