Applying for Observing Time

Telescope time for ESO telescopes on Paranal and La Silla is allocated twice a year in periods of 6 months. Allocation periods run from 1 October through 31 March, and from 1 April through 30 September. Applications for observing time on ESO telescopes may only be submittedvia the p1 interface (instructions can be found here).

You cannot submit proposals for the regular cycles now.
Please wait for the next announcement of observing time
which will be released end of February  2020.

For your convenience you can look at the historic period 105 CfP.
The Late Breaking News page contains updates regarding proposal submission.


Up to 5% of the general observing time may be used for Director's Discretionary Time Proposals (DDT proposals). For detailed information about DDT proposals see the separate DDT Proposal page. As of 1 April, 2019 proposals must be submitted via the p1 interface (instructions can be found here).

For sudden astronomical events requiring urgent or even immediate observations, detailed requests can be submitted. A detailed description of ESO's "Target of Opportunity" POLICY (ToO) is given in a separate document. Please read it carefully before submitting any ToO.


Information about Observing Programmes


Call for letters of intent for public spectroscopic surveys with 4MOST


In preparation of the start of operations with 4MOST,  a call for letters of intent for public spectroscopic surveys has been issued. A public survey is understood to be an observing programme in which the investigators commit to produce and make publicly available a fully reduced and scientifically usable data set that is likely to answer a major scientific question, be of general use and of broad interest to the astronomical community. The raw data are public immediately. Please also consult the 4MOST Survey Policies.


The deadline for sending letters of intent for public spectroscopic surveys with 4MOST is: 

28 February 2020 12:00 CET


Letters should be submitted only in PDF format to using the Word format available below. The Public Spectroscopic Panel (PSP), composed of experts from the community, will review the letters. Recommended surveys will be invited to submit full proposals (mid 2020). The ESO Director General will select the successful public surveys based on the recommendations of the PSP and OPC, which will evaluate their scientific excellence and their technical feasibility.  The selected teams will be invited to prepare a survey management plan, whose approval by ESO is mandatory before final acceptance of a public survey.

Astronomers affiliated to Chilean institutions are cordially invited to submit proposals for surveys with 4MOST, either in participative or non-participative survey modes. ESO will guarantee that meritorious proposals from Chilean PIs will obtain 10% of the total time, where time is computed as exposure time times the number of available fibres for target exposure. Proposers are strongly encouraged to consider submitting proposals for participating surveys, as there is potential for higher science return.

Relevant informations:


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