Applying for ESO observing time

The Call for Proposals for Period 111 has been announced (for observations between 1 April 2023 – 30 September 2023). 

Proposal deadline

Tuesday 27 September 2022 at noon Central European Summer Time (8pm Australian Eastern Standard Time, 6pm Australian Western Standard Time).

Under the terms of the Strategic Partnership between ESO and Australia, Australian-based astronomers have access to the facilities of the La Silla and Paranal Observatories, specifically the:

  • 3.6-m telescope (3.6);

  • New Technology Telescope (NTT);

  • Very Large Telescope (VLT); and

  • Very Large Telescope Interferometer (VLTI).

Complete details on how to apply can be found at the P111 Call for Proposals web page. All applicants should consult the Call for Proposals document for Period 111, and are required to update their ESO User Portal accounts to submit or be on proposals.

Any questions about policies or the practical aspects of proposal preparation should be addressed to the ESO Observing Programmes Office, [email protected]. Applicants who may wish to seek advice on proposal or observing strategies, optimal choice of instrument, etc. are invited to contact AAL’s ESO Program Manager at [email protected].


What’s new in Period 111?

Applicants are strongly encouraged to review the expected changes in instrumentation offered and procedures for Period 111 given in Sec. 1.1 of the Call for Proposals. Among the items likely to be of most interest to the Australian community are:

Distributed Peer Review: With effect from P110,  ESO introduced a Distributed Peer Review (DPR) process for proposals requesting a total time (including overheads) of less than 16 hours, with the exception of proposals including at least one ToO run; proposals for Calibration Programmes; and DDT proposals. All other proposals submitted for P111 will be reviewed in the usual way by the OPC and its sub-panels. PIs of proposals qualifying for DPR accept that their proposals are reviewed by ten peers who have also submitted proposals in P111, and consent to reviewing ten proposals submitted by their peers as laid out in the DPR rules and guidelines. The PI may elect to delegate the reviewer’s role to one of the co-Is listed in the proposal.

Visitor Mode: Requests for Visitor Mode observations may be submitted (and are encouraged for new users in particular) for P111, although any scheduled runs may need to be executed in Designated Visitor Mode instead should travel restrictions be reimposed. Flights to and from Santiago on LATAM via Auckland have resumed, and direct Qantas services between Sydney and Santiago are expected to resume by the end of 2022. ESO will cover the costs for one observer per Visitor Mode run, and may also cover the costs of an accompanying student observer.

ERIS on the VLT: The Enhanced Resolution Imaging Spectrograph (ERIS) is currently being commissioned on UT4, and will be offered in selected modes only in Period 111. The instrument consists of an integral field spectrograph (SPIFFIER) and an imaging camera (NIX). The IFS provides medium-resolution (R ≈5000 to 10000) spectroscopy in the near-infrared over a 1-8 arcsecond field of view with either natural guide star (NGS) or laser guide star (LGS) supported adaptive optics, or in seeing-limited mode. NIX provides diffraction-limited imaging over either a 30 or 60 arcsecond field of view, between the J and M-bands, also with either NGS or LGS supported adaptive optics, or in seeing-limited mode. NIX can also be used in conjunction with an apodising phase plate coronagraph for high-contrast imaging.

NIRPS on the 3.6m: The Near Infra-Red Planet Searcher (NIRPS) is currently still under commissioning and is not yet fully characterised but will be offered as of Period 111. NIRPS is a near-infrared (971nm-1854nm), high-resolution (up to R = 84,000), cross-dispersed (70 orders) fibre-fed spectrograph optimised for stability and designed for the detection and characterisation of exoplanets around late-type stars. It can be used simultaneously with HARPS to collect spectra from 380nm to 1854nm (with a gap from 689nm to 971nm) in a single acquisition. Its ultimate goal is to reach a long-term stability of ≤1 m/s, but for the first Period a more conservative value of 3 m/s is adopted. A Laser Frequency Comb for wavelength calibrations is expected to improve further the stability from Period 112 onwards.

NTT: SOFI is expected to be decommissioned in Period 111 for the installation and commissioning of SoXS, while EFOSC2 will be decommissioned once SoXS enters regular operations on the NTT, which is expected for Period 112.

Scientific keywords: Starting in P110, a new set of scientific keywords replaces the traditional 4 OPC categories. From the p1 interface users must select at least two keywords, and at most five keywords (ten for Large Programmes). The keywords must be selected in decreasing order of relevance (i.e., the first selected keyword is the most relevant).

No new Large Programme proposals accepted in P111: Large Programme proposals (those seeking >100 hrs over 1-4 Periods) are only accepted once per year during the Call for even-numbered Periods

Proposal anonymisation: The Dual-Anonymous Peer Review (DAPR) is now fully deployed, after being introduced successfully in Period 108. Applicants must formulate the scientific rationales of their proposals following these anonymisation rules and examples, which includes a detailed description of the DAPR paradigm. Failure to abide by the DAPR rules may lead to the disqualification of the proposal.


Australian ESO Proposal Workshop 2022 

AAL and Australia’s ESO Scientific Technical Committee and Users Committee representatives (Michael Murphy and Sarah Sweet, respectively) would like to invite our community to an on-line ESO proposal writing workshop to be held on Thursday 8 Sep from noon-2:30pm AEST (10am-12:30pm AWST). Topics to be covered include:

  • The Observing Programmes Committee Process
  • Summary of current and imminent ESO instrumentation
  • The Dual-Anonymous Proposal & Distributed Peer Review processes

followed by a round-table discussion involving a panel of major users of ESO and past OPC members about what makes a compelling proposal, and common mistakes to avoid. Participants will have the opportunity to pitch ideas for proposals to the panel for helpful feedback.

If you are interested in participating in this workshop, please register in advance by going to:

After registering, you will receive a confirmation email containing information about joining the meeting. A recording of the workshop will be made available afterwards upon request for anyone unable to join the event live.

Important Data Privacy Notice for all recent and intending Australian ESO applicants

ESO supplies AAL with telescope/instrument demand and time allocation data relating to Australian astronomers only. Australian ESO applicant data is used only for statistical purposes, and will only be published or made available to other third parties such as AAL member institutions, in aggregated and anonymised form. ESO’s data collection/use provisions are available on the AAL ESO Forum for reference. It may be necessary to use automated data matching from data provided to the Data Central Lens proposal database to confirm the identity of ESO applicants. Applicants may opt out of providing data for Australian statistical purposes (including those from P101-P109 inclusive) by contacting [email protected].